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Preventing Low Birthweight (1985)

Chapter: 8. Improving the Content of Prenatal Care

« Previous: 7. Ensuring Access to Prenatal Care
Suggested Citation:"8. Improving the Content of Prenatal Care." Institute of Medicine. 1985. Preventing Low Birthweight. Washington, DC: The National Academies Press. doi: 10.17226/511.
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CHAPTER 8 Improving the Content of Prenatal Care The data reviewed in Chapters 3 and 6 demonstrate that participation in prenatal care in its current form is associated with a reduced incidence of low birthweight. The data also raise the possibility that the capacity of prenatal services to prevent low birthweight could be increased by emphasizing certain elements of its content. Prenatal care undoubtedly has contributed to the recent reduction in neonatal mortality (Chapter 1~. The challenge now is to build on this success and on new developments in maternity services to increase the capacity of prenatal care to prevent low birthweight. This perspective forms the basis of the four conclusions explored in th is chapter: 1. Increased prominence should be given to certain elements of prenatal care, many of which are relatively low in technological complexity; and further, prenatal care should be increasingly tailored to meet the widely varying needs and risk profiles of individual pregnant women. 2. Interventions closely associated with prenatal services can help to reduce low birthweight, particularly programs aimed at smoking reduction and better nutrition. Stress alleviation approaches also may prove valuable. 3. Strategies are available to encourage provision of improved, more flexible prenatal care, particularly for women at elevated risk of low birthweight. Prevision of professional practice standards, federal leadership, provider education, and changes in reimbursement practices are discussed.) 4. Over the longer term, the full promise of prenatal care for preventing low birthweight lies In research on its content, including the effectiveness of its individual components and the value of various combinations of interventions. Based on the information summarized in Part I, the committee calls attention in this section to selected elements of prenatal care that are particularly important to the detection and prevention of low birthweight. Most of the care components discussed below are mentioned in the Standards for Obstetric-Gynecologic Services, published by the . . American College of Obstetricians and Gynecologists (ACOG} ,~ anc 175

176 also in the Guidelines for Perinatal Care, developed jointly by the . American Academy of Pediatrics and ACOG.2 By highlighting them in this report, the committee hopes to increase their prominence in prenatal services and to strengthen the consensus among maternity car e providers that these components of care are essential, not marginal elements of good prenatal services, and are especially important in preventing low birthweight. The following section outlines areas for increased emphasis in the services provided to all pregnant women; to women at elevated risk of preterm delivery; and to women at elevated risk of intrauterine growth retardation (IUGR). Care for All Pregnant Women The committee has identified seven components of the prenatal care offered to all pregnant women that mer it increased emphasis in the effort to improve pregnancy outcome generally and to prevent both preterm delivery and IUGR in particular. 1. Establishing Explicit Goals Greater efforts to organize prenatal care around explicit goals can help focus the attention of the patient on the purposes of the prenatal visits and engage her more in her own care; the process of establishing goals also can help the practitioner to structure appropr late interventions. Reducing the risks of preterm delivery and intrauterine growth retardation are two such goals; other important ones include the prevention of per~natal mortality and fetal anomalies, and preparation for labor and delivery. Defining the prevention of low birthweight as an explicit goal of prenatal care may require adjustments in clinical practices For example, more prenatal visits early in pregnancy may be appropriate. At present, prenatal care seems particularly oriented toward the prevention, detection, and treatment of problems that are manifested in the third trimester, particularly preeclampsia--thus the emphasis on blood pressure monitoring, screening for proteinuria, attention to possible edema, and increased frequency of prenatal visits toward the end of pregnancy. By contrast, the goal of preventing low birthweight r equires additional attention dur ing the first and second tr imesters especially to screening, diagnosis, and treatment, as early as pass ible, of conditions that predispose to preterm labor or IUGR, such as smoking and poor nub' tional status. These problems should be addressed earlier In pregnancy (or, ideally, before conception, as discussed in Chapter 5), and in a more concentrated fashion, than the current schedule of visits permits. 2. Risk Assessment Prenatal care should include formal evaluation of risk, which may be facilitated by using risk assessment scoring systems such as those described in Chapter 2. Risk assessment must be a dynamic process--assessment should begin at the first visit early in

177 pregnancy and be followed by repeated evaluations to identify developing problems . Once patients are identif fed as high r isk, a specif ic plan must be made to reduce the risk conditions where possible. Screening for elevated r isk of low birthweight typically involves consideration of sociodemographic factors, such as age, race, educa- tional level, mar ital status, and ~ ncome, as well as character istics of the woman ' s personal and physical environment, and possible sources of psychosocial stress. Assessments also focus on obstetric history, general medical history ~ including the presence of genetic r isks), and behaviors known to increase the risk of a poor pregnancy outcome, such as smoking and alcohol or other substance abuse.3 Risk assessment can help to increase the flexibility of prenatal care. A review of each patient's history and current situation enables health care provider s to design individualized prenatal care plans . This flexibility is particularly important for women in sociall y d isadvantaged, high-risk groups; set packages of prenatal care often are not flexible enough to manage their multiple problems. The importance of risk assessment is underscored by evidence suggesting the need for more careful diagnosis of problems during the prenatal period. For example, Ha11 et al. reviewed the records of 2,186 women from the city district of Aberdeen who delivered in 1975 and found that less than half the cases of intrauterine growth retardation were detected by the clinician antenatally; related problems of misdiagnosis and overdiagnosis are also descr ibed by the authors. 4 Similarly, it has been suggested that in a significant proportion of pregnancies, hypertension is underd~agnosed; or even if diagnosed, is not treated adequately. s Pregnancies burdened by hypertension are more likely to culminate in growth-retarded infants and are more difficult to manage during labor. Infections, too, may go unrecognized and untreated during pregnancy. For example, some data point to asymptomatic bacteriuria as a potential cause of low birth- weight (Chapter 2~' yet in many prenatal settings, no attention to detecting asymptomatic bacteriuria occurs. Risk assessment can help to focus attention on such risk factors. 3. Pregnancy Dating Accurate dating of pregnancy is a cornerstone of good prenatal care. Without it, a clinician is less able to detect intrauterine growth retardation, to determine if labor is premature or how premature it might be, or to avoid iatrogenic prematurity that can · . · . ~ ~ . ~ ~ ~ _ ~ ~ be associated with elective Induction of labor and nonemergency cesarean section. The minimum data required to determine gestatzonal age include the date of the beginning of the last menstrual period, uterine size by pelvic exam during the first trimester, date of quickening, date on which Me fetal heart tones are first heard by ascultation, and serial fundal height measurements after 20 weeks gestation. When a uterine s ize-date discrepancy exists early in pregnancy, ultrasound can help to establish gestatzonal age.

178 4. Ultrasound Imaging Ultrasonography has become a highly developed technology capable of detecting many problems associated with both preterm delivery and with infants that are small for gestational age. In particular, ultrasonography can help to date pregnancies accurately and to monitor fetal growth and development. It has therefore become an important component of prenatal care directed at preventing low birthweight and other poor outcomes. In February 1984, the National Institutes of Health and the Food and Drug Administration sponsored a consensus development conference to assess the use of diagnostic ultrasound imaging in pregnancy.6 The conference concluded that routine ultrasound examination of all pregnancies is not supported by available data. Almost 30 specific indications for ultrasound examination were identified, however; many of these are relevant to planning care for women at risk of low birthweight. Selected indications include estimation of fetal weight or fetal presentation in premature rupture of membranes or premature labor; evaluation of fetal condition in late reg istrants for prenatal care; evaluation of fetal growth when there is an identified cause of uteroplacental insufficiency, such as severe preeclampsia, or when other medical complications of pregnancy predisposing to fetal malnutrition are suspected; significant uterine size/clinical dates discrepancy as determined by serial fundal height measurements; and serial evaluation of fetal growth in multiple gestation. 5. Detection and Management of Behavioral Risks Prenatal care, and particularly periodic risk assessment, should include explicit attention to detecting behavioral risks associated with low b~rth- weight, especially smoking, nutritional inadequacies such as poor weight gain, and moderate to heavy alcohol use {and substance abuse generally). When such problems are identif led, attempts should be made to modify them. In many settings, the intervention options are limited to physician or nurse counseling of the pregnant woman; in others, more formal programs are available on a referral basis. Selected inter- vention programs are reviewed later in this chapter. Here, the point is simply that practitioners should talk with their patients to determine the existence and degree of these health-compromising r isks and bring to bear the best interventions available. - 6. Prenatal Education There is widespread suppor t for more and better health education for women who are pregnant or contemplating pregnancy.7 ~ Nonetheless, education and counseling services often are inadequate, particularly for high-risk populations. Some settings, such as health maintenance organizations, try to emphasize such care, but many do not. A variety of approaches to education and counseling , . . . . . . . ~ have been used: one-to-one counseling, group discussions, audiovisual and written materials, and Remit interviews" with a nurse who clarifies and reinforces medical recommendations made during a health care visit.9 A

179 Topics relevant to prevention of low birthweight that should be stressed in the prenatal period include: · behavioral r isks in pregnancy, noted above; · early s igns and symptoms of pregnancy complications, including signs of preterm labor, vaginal infection, and other medical problems, and the importance of their early detection; and · the role that prenatal care plays in improving the outcome of pregnancy and the importance of keeping prenatal care appointments. These topics should be included in prenatal education along with the more colon ones of preparation for labor and delivery, the immediate postpartum period, infant feeding, family planning, locating a pedants iczan and selecting a delivery site . Chapter 5 includes additional discussion of health education topics, though from the perspective of the interval before pregnancy. Problems that interfere with effective education of pregnant women include the short time typically scheduled for each prenatal visit, third-party reimbursement policies that pay for diagnostic and therapeutic procedures but ignore provider costs related to patient education; and lack of patient-education interest and skills on the part of many physicians. This last reason suggests that nurses and related personnel may be more appropriate than physicians as providers of prenatal education. 7 Childbirth education classes possibly could play an important role in efforts to reduce low birthweight through prenatal education. Such classes are rapidly becoming an accepted part of prenatal care in the United States. Figures from some communities suggest that between 30 and 50 percent of mothers attend some form of prenatal class. To contribute more to prevention of low birthweight, however, such classes (and indeed, patient education generally) should begin earlier in pregnancy, particularly to overcome behavioral risks. Currently, these classes usually do not begin until the third trimester of pregnancy. Also, the curriculum should place greater emphasis on the prenatal per iod, expanding beyond the usual focus on labor and birth to include the topics noted above. ~ 3 Another limitation of these classes is that they do not reach all portions of society equally. Numerous studies have shown that participants in childbirth education courses tend to be married women who are older, better educated, of a higher socioeconomic group, more likely to hold good jobs, and more positive about their pregnancies than are the women who do not per ticipate.~ Accordingly, efforts should be made to enroll in these classes more pregnant women from those groups that often fail to take advantage of them, particularly because many such women are at high risk of low birthweight on the basis of social, economic, and behavioral factors. The effect of childbirth classes on pregnancy outcome has been difficult to measure. Controlled studies have found that the classes are effective in reducing the need for analgesia and anesthesia during labor, even among a group of very low-income women. ~ s ~ 6 However, neither of two controlled studies that looked for an association

180 between the classes and low birthwe~ght found any effect. 17 This may reflect in part the emphasis on labor and delivery classes. Preventing low birthwe~ght is rarely addressed. low birthwe~ght found any emphasis on labor and delivery == ^~ - . . in these 7. Health Care System Factors Chapter 7 presented several health system characteristics that can lead to increased access to prenatal care. Several of these also could be regarded as content-of-care issues, and thus they are repeated here in the context of improving prenatal care for all women: · the importance of communication between patients and informed staff to answer patients' questions about prenatal problems and to encourage patients to report relevant signs, symptoms, and problems; · the intangible but essential role of a caring atmosphere in which providers pay close attention to patient attitudes, feelings, responses and complaints, and are sensitive to language and cultural barr iers; and · the importance of transportation and child care services. Also, prenatal care providers need to organize their services so that a wider variety of patient problems and risk factors can be managed, either directly or through well-organized referrals, e.g., for nutrition-related care, psychosocial counseling, and help in modifying smoking and other health compromising behaviors. Team approaches can help to provide multiple services, although the risk of fragmentation and too many care providers remains a potential problem. Care for Women at Risk of Preterm Delivery The information presented in Chapter 2 on the etiology of prematur- ity and the risk factors associated with it have led several groups to organize innovative programs aimed at preventing preterm delivery; three such programs are outlined in Appendix C. The committee has reviewed preliminary data from these and related programs. The committee concluded that expanding prenatal care in several specific ways is likely to reduce the chances of preterm delivery in women judged through risk assessment to be at elevated risk of such an outcome. These additional activities build on the seven areas of emphasis described above. 1. Risk Assessment A woman who is at higher than average risk of preterm labor requires repeated risk assessment as her pregnancy proceeds. In particular, women who have been defined as high risk because of a previous preterm birth or mid-pregnancy loss may require additional cervical assessments in the second half of pregnancy to check for ear ly signs of dilatation or effacement. The committee is aware that the value and r isks of repeated pelvic examinations in later pregnancy have not been clearly assessed.

181 2. Patient Education Women at elevated risk of preterm delivery should be offered special education about the factors associated with prematur ity; the importance of early detection of the symptoms of preterm labor, such as bleeding and per iodic contractions ; how to detect mild uter ine contractions and how to differentiate normal contractions that often occur throughout pregnancy from those signaling early labor; and what to do when the signs and symptoms of preterm labor appear, including how to contact an obstetr ic care provider or facility for consultation and help. Efforts to arrest preterm labor can hinge on its early detection and prompt management. Higher isk women also should be taught to identify and lessen events in their daily lives, such as physical stress and strenuous exercise, that can trigger uterine contractions, which in turn might lead to preterm labor. The research data supporting such advice are still tentative, but common sense and clinical judgment support such caution e 3. Provider Education Patient education should be supplemented by education of prenatal care providers about the topics mentioned above and others, including: (1) the importance of being receptive to patient problems and complaints that may be early signs of preterm labor; (2 the need for prompt identif ication of preterm labor, and the uses of hospitalization for observation and possible treatment; and (3 ~ the var ious approaches available for arresting true preterm labor . Clinicians also need to learn how to revise their practice patterns to accommodate the increased time and attention that such high-risk women often require. Educating patients about the r isks, signs, and symptoms of preterm labor is of limited value if health care providers are not organized to be responsive to such factors. In particular, encouraging a woman to call if she believes preterm labor is under way requires that procedures be in place for admitting the woman into the hospital rapidly for observation and/or treatment if necessary. Several hours delay can decrease the likelihood of arresting preterm labor. Finally, it is important for providers to recognize clearly the risl: of iatrogenic prematurity and to ensure fetal lung maturity and a gestational age of at least 3 7 weeks before elective induction of labor or performance of a nonemergency cesarean section. 4. Tocolysis An important approach to reducing the incidence of prematurity has been the use of agents to inhibit preterm labor. Agents known to inhibit labor include alcohol and prostaglandin synthetase inhibitors, but these are accompanied by side-effects for mother and neonate that diminish their usefulness. Magnesium sulfate also inhibits uter ine contractions . Another class of labor inhibitors are the var. ions betamimetic drugs, several of which have been developed and marketed for many years in other countr ies . These include isox- suprine hydrochlor ice, salbutamol, terbutaline r r itodr fine hydrochlor ice, and hexaprenaline. Only ritodrine has been licensed as a betamimet~c for use in the United States for inhibition of premature labor. It was licensed in 1980, following initiation of clinical trials in 1972.~9 20

182 Such agents, to be useful, must inhibit labor for a significant period of time and prolong pregnancy until the duration of gestation consistent with a reduction in per~natal mortality due to preterm birth. The development of research protocols to identify and test such drugs, often called "tocolytic agents," is difficult. Uterine contrac- tions frequently occur during the latter part of pregnancy, and thus it is often difficult to differentiate between normal Braxton HiCkSt contractions and true preterm labor leading to cervical dilatation. Uterine contractions may be painful or painless and may be accompanied or unaccompanied by cervical effacement and dilatation. Contractions may cease spontaneously or with bedrest, and they may or may not be stopped by hydration or mild sedation. If tocolytic agents are withheld until cervical effacement and/or dilatation are detected to confirm the diagnosis of true labor, inhibition of labor may fail; but if cervical changes are not confirmed, it is difficult to know whether contractions would have stopped spontaneously or if only false labor was present. Patients with ruptured membranes, significant cervical effacement, or dilatation greater than 4 or 5 centimeters usually progress to delivery despite tocolytic agents. Many patients with preterm labor have medical or obstetric complications that contraindicate the use of tocolytic agents, and in cases of vaginal bleeding, chor ioamnzonitis, severe preeclampsia, and other obstetric complications, delivery may be in the best interests of mother and fetus. Side-effects produced by tocolytic agents include decreased peripheral resistance, decreased blood pressure, tachycardia, and frequently, palpitation and chest pain; rarely, pulmonary edema may be life threatening or even fatally 20 Current exper fence with tocolysis, which is now extensive, suggests several conclus ions . First, In individual cases of threatened preterm labor, tocolytic therapy can often be effective, though not always. It is nonetheless true that on a population basis, tocolysis has had little impact, as evidenced by the relatively minimal decline in the incidence of prematurity since the licensing and widespread use of ritodrine. This apparent paradox is probably explained in part by the failure to use tocolytic drugs in all suitable cases; the failure to use such agents until labor is well established, which decreases their efficacy significantly; and the number of contraindications and side-effects that limit the pool of pregnant women who could benefit from tocolysis. The indications for and proper use of tocolytic agents need further definition and more widespread dissemination. In particular, the vital importance of early diagnosis of preterm labor must be stressed. It is likely that if both patients and providers were better informed about the early signs and symptoms of preterm labor and about the uses of tocolytic therapy, the namer of cases in which tocolytic intervention could be used effectively would increase. Huezar and Naftol~n report that at present, only about one-third of pregnant patients who arrive at the hospital in preterm labor are suitable candidates for tocolytic therapy, although they do not describe the reasons why the other two thirds are not; presumably, some have contraindications and many are in advanced stages of labor.2 ~ It is also apparent that because of the various contraindications for use of tocolytic agents and because of their side-effects, noted above, the current generation of tocolytic

183 drugs cannot be viewed as the long-term solution to the problem of prematurity. Care for Women at Risk of Intrauterine Growth Retardation Many of the risk factors associated with preterm labor also are associated with intrauterine growth retardation (IUGR). Thus, the emphases in prenatal care appropriate for prevention of preterm labor often overlap with those for prevention of IUGR. For example, careful risk assessment is as important for IUGR detection and treatment as for prematur ity . Nonetheless, thr ee points spec if ic to TUGS can be emphas ized: 1. Behavioral Risks Behavioral risks are a signi ficant factor in fetal growth retardation. Women identif fed as being at elevated risk of IUGR should be encouraged to pay vigorous attention particularly to smoking reduction and to avoidance of heavy or moderate alcohol use. 2. Nutrition Maternal preconception weight and weight gain during pregnancy are major determinants of birthweight (Chapter 21. The rate of weight gain during the third tr imester is a particularly important determinant of birthweight.2 2 Thus, monitoring adequate weight gain and offering nutr itional surveillance and counseling, while central to prenatal care generally, are particularly important for women j udged to be at elevated r isk of IUGR. Both the content and organization of nutrition services in prenatal care have been defined,23 and they should be major components of high quality prenatal care, especially for higher isk women . 3. Assessment of Gestational Age and of Fetal Growth and Maturity Although important for prenatal care generally, accurate assessment of gestational age and of fetal growth and maturity is critical to the early diagnosis and effective management of intra- uterine growth retardation. As noted earlier, ultrasonography can help to establish gestational age when uterine size-date discrepancies are noted. Programs Complementary to Prenatal Care Because many of the risks associated with low birthweight have a behavioral basis, the committee examined selected interventions intended to reduce behavioral risks, including smoking reduction programs for pregnant women and nutrition intervention programs such as the Special Supplemental Food Program for Women, Infants and Children (WIC). The committee also inquired into stress and fatigue abatement approaches . Even though the data demonstrating a role for such risk

184 factors in low birthweight are controversial (Chapter 2), their potential importance is great. Special efforts were made to determine whether interventions in all three areas could be linked to improvements in birthweight. The interventions reviewed are not, strictly speaking, components of prenatal care, but they should be adjuncts to more routine prenatal services. Research questions in each area are numerous. But it is the committee's judgment that while research proceeds, common sense and a growing body of data suggest that elements of these programs are useful and should be linked to prenatal care, either directly or through r eferral . Smoking Reduction Programs Several types of programs have been developed in var ~ ous settings to help pregnant women stop or reduce their smoking habit. Most are based on the finding that pregnancy alone provides a strong incentive to stop smoking. About 20 to 25 percent of women who smoke at the beginning of pregnancy quit on their own at some time during the 9 months. Controlled studies suggest that aggressive intervention programs can encourage up to 30 percent more (beyond those who quit spontaneously) to stop. Unfortunately, about 80 percent of women who quit during pregnancy begin smoking again after delivery.2 4 Most studies to evaluate smoking cessation programs focus on one or more of the three most common forms of intervention: one-to-one counseling by a physician or other health professional; group counseling; and provision.of self-help materials. One of the earliest studies In this area examined the effect of physician advice. In a randomized controlled study performed in Britain in 1977, 280 pregnant smokers who received smoking cessation advice were compared with 308 who did not. Twenty-seven percent of the study group stopped smoking compared with 4 percent of the controls; however, half of the advised ~ . · . . women who quit resumed smoking later in pregnancy. Interviews With women receiving advice indicated that health education and physician advice raised their motivation to quit but did not offer enough "practical help. n This study also suggested the need for repetition of advice during pregnancy.2 s A recent 3-year study by Sexton et al. demonstrated an association between a smoking cessation program and improved birthweight. Over 900 pregnant smokers from a population shown to be at relatively high risk of poor pregnancy outcome were randomly allocated to an intervention or a control group. The intervention group received special assistance and encouragement to stop smoking in the form of information, support, practical guidance, and behavior modification methods. The control group received the usual prenatal advice from their obstetricians. Forty-three percent of the intervention group stopped smoking, but only 20 percent of the control group did. In addition, treatment group infants (single live births) were 92 grams heavier and 0.6 centimeters longer than control group infants. The lesser weight and length

185 related to smoking could not be fully explained by gestational age. These findings suggest that some fetal growth retardation can be overcome by the provision of antismoking assistance to pregnant women. 2 6 Group techniques, as distinguished from one-to-one physician advice, often have been advocated in health promotion because they appear to be more efficient. In a study of the Raiserrpermanente Medical Care Program in Portland, Oreg., Loeb et al. found that groups were not a cost-effective intervention in the area of smoking and pregnancy. They urge, instead, that resources be available for individual counseling at the time of the prenatal care vi sit. Groups may be effective, however, as reinforcement and support for individual counseling . 2 7 The "self-care" approach to smoking in pregnancy was studied by Ershoff et al. at the Maxicare HMO in Hawthorne, Calif. The project evaluated a home correspondence smoking cessation program in which the intervention group received printed materials on a weekly basis and called in three times a week to listen to tape-recorded reinforcing messages . More women in the experimental group (49 percent) quit sack ing than in the control group ~ 37 . 5 percent) . Er shof f et al. estimated that up to a third of pregnant smokers tend to quit on their own, and another third can be reached through intervention. The ma jor limitations of the study were the lack of randomization and the small sample size (N = 129) .2 ~ Several observations made by Ershoff et al. have implications for future programs. They borsch uded that it appears worthwhile to provide some form of maintenance effort for women who stop smoking at pregnancy onset. For some women, abstinence in the early stages of pregnancy may be precipitated solely by the experience of nausea, and once the symp- toms abate, the temptation to return to smoking may be quite strong. For others, concerns about the health consequences of smoking dur ing pregnancy may provide the impetus for attempting to quit initially, but may not be sufficiently strong to maintain cessation over the entire course of pregnancy. Another type of intervention program recognizes the importance of involving the woman's partner in smoking cessation programs .2 9 Based on the understanding that it is more difficult for a woman to stop smoking if other members of the household smoke, Wilner et al. developed a special intervention approach, "Quitting for Two, n that includes materials directed at partners. The program features written guides that can }'e used either in small group sessions or distr ibuted by clinicians as a self-care program. The authors suggest, for example, thank materials be distributed in pediatrician's offices--a good opportunity to reach families in the ch~ldbear ing years . The materials can also be made available through childbirth preparation classes; such classes offer a special opportunity for reaching beyond the pregnant woman because spouses/partners usually attend. An important component of this program is that it encourages women planning or considering pregnancy to join. Results of the program are not yet available.

186 Several themes emerge from these and other programs. First, some studies suggest that social support is a critical factor in changing smoking behavior. Spouses, partners, and other family members need to be involved in intervention efforts. Second, prenatal care providers should be reasonable in their expectation that a pregnant woman will give up an addictive habit. The effectiveness of potismoking advice and intervention may be negated if too much is attempted. A pregnant woman is often asked to alter her eating habits, avoid alcohol, perhaps to reduce her overall stress, attend prenatal classes, and avoid drugs. These recommended changes are superimposed on fatigue, shifts in body image, and other sexual and social changes associated with pregnancy and planning for a new baby. Prenatal care providers need to consider whether it is advisable to ask that many behaviors be changed simultaneously; they may need to choose those of highest priority, of which smoking is undoubtedly one. Third, counseling by the physician or other primary clinician appears to be among the most effective intervention strategies for the pregnant smoker, particularly given the regular schedule of prenatal visits. Last year, the American Lung Associaton published a special kit for obstetricians on how to counsel their pregnant patients who smoke. Such efforts need to be reinforced by both patient and provider education. Fourth, use of the mass media continues to play a motivating and reinforcing role, but probably is insuff icient as a single intervention (Chapter 9~. Attractive marketing strategies, public service announce- ments, and posters should be supplemented by cigarette labels that explicitly warn of the hazards of smoking during pregnancy. Fifth, a host of research issues can be identified. For example, we need a much better understanding of the components of effective intervention strategies. It is unlikely that one intervention will be appropriate for all pregnant smokers ; we need to know specifically which types of women respond best to individual counseling, groups, and self-care approaches . In par titular, we need to learn more about how to structure interventions directed at pregnant adolescents who smoke and smokers who also drink, and about strategies for multiparous versus pruniparous smokers, because these two groups appear to differ in their smoking practices. Research is also needed on the motivations of women who do stop successfully during pregnancy. Some women have reported stopping due to nausea, others out of concern for the baby, and others because of physician advice. Studies should probe the origins of these motivations and how they can be used to strengthen intervention approaches. Further, maintenance strategies must be given additional attention. This holds not only for continued cessation through the pregnancy, but for postpartum behavior as well. Single-episode interventions probably will be ineffective in the long term. The role of social supports such as the spouse needs to be further evaluated, particularly as a component of maintenance. In sum, there is no question that smoking reduction or cessation is possible In pregnancy and that it has the potential to play a major role In any overall strategy to reduce low birthweight. Accordingly:

187 The committee urges that helping women stop or reduce smok- ing in pregnancy become a major concern of obstetric care providers. Research to define how best to address the smok- ing problem should receive high priority; simultaneously, ant~smak~ng advice should be offered routinely by physi- cians and other maternity care providers and supplemented, where possible, by educational materials, media-based messages, and related strategies. Prenatal Nutrition Intervention: WIC The nutrition data reviewed in Chapter 2 support the view that nutritional assessment and services should be major components of high- quality prenatal care, especially for women at elevated risk of IUGR. Accordingly, the committee examined the value of the Special Supple- mental Food Program for Women, Infants and Children (WIC), which provides one of the principal data sets demonstrating the importance of nutrition to birthwe~ght and represents a major public investment In the nutritional well-being of women and children. WIC is directed at high-risk pregnant and lactating women, infants, and children up to age 5 who meet certain income and nutritional-risk eligibility standards. For pregnant women, WIC provides vouchers to purchase nutritious foods, education about nutrition, and close referral ties to prenatal services. About 500,000 women receive WIC services each year, representing about 15 percent of total U.S. births. Once these high-risk women enter the WIC program, more than 90 percent participate fully until they give birth. 3 0 Evaluation studies show that prenatal participation in the WIC program Is associated with improved pregnancy outcomes.30~33 Wile all of the studies have some methodologic problems--WIC evaluations are particularly hindered by difficulties in obtaining an appropriate comparison population and in securing a representative WIC sa'eple--the similarity of their results supports the overall conclusion that the WIC program provides positive benefits to nutritionally and financially h~gh-risk pregnant women. Of particular relevance to this report is the decrease In low birthweight incidence associated with WIC participation. Rennedy et al. reported a 33 percent decrease in low birthweight status among the babies of participating women in comparison to a control group; 3 2 Rotelchuck et al., a 21 percent decrease; 3 ° and Rotelchuck and Anderka, a 22 percent decrease.3 ~ Metcoff et al.3 3 and Rotelchuck and Anderka also reported significant decreases in the incidence of small for gestational age babies born to women who were WIC participants. 3 ~ Although a recent report by the U.S. General Accounting Off ice (GAO) notes that the quality of the evidence regarding WIC program effects is uneven, the report also states that the evidence of program benefit Is strongest for increases in mean birthweight and decreases in the percentage of low birthwei'3ht infants. Isis of the WIC studies containing information about infant birthweights are of high or medium

188 quality. They give some support, but not conclusive evidence, for the claims that WIC increases infant birthweights. In these studies, about 7.9 percent of the mothers in WIC had infants who were less than 2,500 grams at birth, compared to about 9.5 percent of the mothers who were not in WIC. ThiS translated into the positive finding that, in the six studies, the proportion of infants who are 'at risk' at birth because of low weight decreased as much as 20 percent. Average birthweight were between 30 and 50 grams greater for WIC participants . ~ 3 5 In another comprehensive review of WIC evaluation studies, Rush et al . concluded: The best estimates are that participation in the WIC program does lead to increased mean birthweight, probably in the range of 20 to 60 grams, with greatest effects among those at highest risk of nutritional causes of low birthweight (women with low weight at conception, blacks, smokers, etc.~. Rates of birthweight under 2500 grams appear to be lowered by about one percent, and possibly as much as two percent, from base rates of around six percent of white births, and 11 or 12 percent of black births. There is reasonably consistent evidence that much of this difference is mediated by increased duration of gestation, and not just accelerated fetal growth. (Towards term, there is about a 25 gram increase In birthweight with each day's prolonged gestation.) These levels of benefit are consistent with past experience with nutritional supplementation in pregnancy. Higher estimates generally arose from studies with suspect design and analyS IS . ~ 3 6 The results of WIC evaluation studies also seem to indicate that early and consistent participation in the program during pregnancy Is related to magnitude of benefit. Edozien et al . ,3 ~ Kotelchuck et al., 3 0 and Schram3 7 all showed that the benef its of WIC accrue principally to prenatal participants of 7 or more months duration. In particular, large reductions in low birthweight incidence are noted for women participating in WIC more than two trimesters, even after controlling for possible confounding of gestational age and duration of per ticipatzon. The GAO resort cited earlier concludes that there is some evidence to suggest that participating in WIC for more than 6 months is associated with larger increases in birthweight and decreases in the proportion of low birthweight infants than shorter per t~cipation periods. A recent report has also suggested that continuing to receive WIC supplementation during the interpregnancy period can help to increase birthweight in subsequent pregnancies. Caan compared the birth outcomes of a group of women who per tic~pated in WIC during a first pregnancy, continued to receive WIC in the interpregnancy period, and remained in the program during a second pregnancy, to a group of women who also participated in WIC during both pregnancies but received very little supplementation in the interpregnancy period. The difference mean birthweight adjusted for gestational age between the two groups was 160 grams.3 ~ WIC is not the only prenatal nutrition intervention program that has been associated with improvement in low birthweight status. Results from other countries are consistent with the WIC results'39 40 although the applicability of the programs evaluated to the United

189 States is unclear. Prenatal participation in the U.S. Commodity Supplemental Food Program also has been associated with a decrease in the low birthweight rate Thong participating women.4 ~ in sum' supplemental food programs seem to be associated with significant reductions in low birthweight. It Is also important to note again that WIC is not simply a nutr ition supplementation program. It is a three-part intervention program involving supplemental food, nutritional counseling, and close ties to prenatal care. Each component is believed to contribute to the improved pregnancy outcome. The value of WIC as a tool for recruiting high-risk women into prenatal care is discussed in Chapter 7. Research has not isolated the differential effects of the three WIC components. The committee urges that nutrition supplementation programs such as WIC be a part of comprehensive strategies to reduce the incidence of low birthweight among higher isk women. Such programs should be closely 1 inked to prenatal services . Stress and Fatigue Alleviation Even though the evidence associating stress with low birthweight is of uneven quality, several programs have tried to reduce the levels of stress experienced by pregnant women In an effort to improve pregnancy outcome. Some are concerned primarily with physical stress and fatigue, others more with psychosoc i al and emotional stress . Although the committee makes no recommendation in this report for a major commitment to stress reduction during pregnancy, it highlights this as potentially an impor tent area. Several approaches to stress reduction are described below to give an indication of current work In this area. Efforts to reduce physical stress to improve pregnancy outcome include the study reported in 1974 by Jeffrey et al. on the effect of bed rest in twin pregnancy. The study concluded that bed rest appeared to reduce perinatal mortality rates; however, when gestations of less than 30 weeks were excluded, bed rest did not significantly alter the perinatal mortality rate or the length of gestation. However, the incidence of small-for-gestatzonal-age infants at all ages over 3 0 weeks was decreased--thus the conclusion that bed rest encourages intrauter ine growth, at least in twin pregnancies.4 2 Reduction of physical stress is also part of Papiernik's low-birthweight prevention program in France (Appendix C). In that program, women with several risk factors (especially a history of preterm delivery, incompetent cervix, and/or a particularly strenuous lifestyle) are advised to reduce stress, especially physical stress, by taking a leave of absence from their jobs or by getting additional help at home from a friend, family member, or paid helper. Approaches to reduce psychosocial and emotional stress include programs that encourage the use of social support networks. For example, Nuckolls et al. found that utilization of social suppor t systems can reduce pregnancy complications among women exposed to multiple life crises during pregnancy.4 3

190 Some programs address psychosocial and physical stress simul- taneously. An example is the March of Dimes continuing education program for nurses developed by Herron and Dulock, which is used in the University of California at San Francisco prematurity prevention program described in Appendix C. '~. TV '=" ~. =~" W-~1 regarding lifestyle factors that can cause excessive fatigue and that may trigger uterine contractions, such as strenuous work or activities, climbing more than three flights of stairs on a routine basis to reach living quarters, and commuting more that 1-1/2 hours daily. In addition, the nurses are instructed to determine whether pregnant women have experienced any event or series of events precipitating unusual anxiety, such as the death of a family member or close friend, loss of employment by either the pregnant woman or her partner, or separation of the pregnant woman from her partner by a dissolved relationship or divorce. Once stresses are identified, the nurses work actively to help the women toward resolution of problems. The nurses also are taught to encourage patients to seek and use the assistance of supportive individuals in their own environments and to refer patients to a social worker or psychiatrist as appropriate.4 4 High-risk patients in the San Francisco program also receive psychological support during pregnancy from a member of the "Preterm Labor Support Group," consisting of nonpregnant women who have experienced p~eterm labor, and are encouraged to develop close relationships with the nurse practitioners who manage their prenatal care.45 Another potentially important stress reducing intervention is maternity leave. In a review of maternity policies in the United States, Ramer man et al. detail the inadequacies of protections for working pregnant women who wish to take leave from work before and/or after childbirth.. 6 The patchwork arrangements in this country of sick leave, disability leave, leave without pay, and other leave categories provide seriously inadequate income and job security for pregnant women and new mothers who participate in the labor force. Inadequate maternity policies also make it exceedingly difficult for women to stop working in later pregnancy to reduce stress-related risk factors, such as employment requiring ions periods of standing. Adequate maternity leave before childbirth may be both helpful and hard to arrange. The committee recognizes that revising maternity policies touches ~ ~ ~ in the labor I_ ~~ ; __; I., MA_ ~~ - . ~ complicated issues concerning women~s per ticipatlon force. It is reasonable to suggest, nonetheless, that more adequate maternity leave, particularly for certain high-risk women, could contribute to the reduction of low birthweight. Labor unions, women's groups, and health professionals at a minimum should direct attention to this major issue. Encouraging Change in Prenatal Services To encourage the provision of improved, more flexible prenatal services, particularly for women at elevated risk of low birthweight,

191 the committee recommends four specif ic strategies . committee r ecommends that: First, the The suggestions made here for strengthening the capacity of prenatal care to reduce the incidence of low birthweight should be reviewed carefully by the professional societies of the major maternity care providers and by others concerned with prenatal care, to determine whether their general guidelines for clinical practice should be revised or enr iched accordingly. These organizations include the American College of Obstetricans and Gynecologists, the American College of Nurse-Midwives, the American Academy of Family Practice, the Nurses Association of the American College of Obstetricians and Gynecologists, the various state level Perinatal Associations, and the American Public Health Association (particularly its Public Health Nursing section ~ . Second, there is a role for federal leadership in enhancing the capacity of prenatal care to reduce low birthweight. By contributing public funds to Medicaid, health departments, community and migrant health centers, and other health services, the federal government is able to influence strongly the content of care it purchases or provides directly. This influence can be used not only to improve prenatal care supported by public funds, but also to improve prenatal care in the private sector by providing a worthy example. Accordingly, the committee urges that: The Division of Maternal and Child Bealth (DMCH), in concert both with consumers and the major professional societies concerned with maternity care, should def ine a model of services to be used in publicly financed facilities providing prenatal care. Such standards should be flexible enough to accommodate the needs of high-risk women; deal not only with clinical/medical issues but also with behavioral issues such as smoking; include formalized risk assessment and adequate health education; and address the major barriers that decrease access to prenatal care. DITCH and appropriate state agencies should be provided with sufficient funds to monitor the adoption of the model in public facilities. A federal statement descr lbing model prenatal care would contribute to a uniform understanding of what the content of prenatal care should be and would help providers tailor care to specific health goals, including prevention of lUGR and preterm labor. It is important that such a statement be updated and revised frequently to incorporate new knowledge and experience and that it be used in a way that does not discourage research on improved approaches to prenatal care. Third, the committee recommends that:

192 The professional societies of the major maternity care providers should undertake educational efforts for their memberships based on the prenatal care elements emphasized in this report. The committee recognizes that the issue of how best to structure education for health care providers is complex. The following are suggested as additions to the existing system of continuing education for clinicians: · Summary articles and reviews on ways to reduce the incidence of low b~rthwe~ght should appear more frequently in professional newsletters and journals . For example, the n technical bulletin series n of the American College of Obstetricians and Gynecologists (ACOG) is believed by ACOG to be read widely by obstetricians and gyncologists and other maternity care providers. Accordingly, ACOG could use this communication source to emphasize to providers the prenatal care i ssues outlined In this report. Similar communications could be used by other organizations. · Individual education/tutorials could be modeled, for example, on the Bowman Gray School of Medicine's Prevention of Prematurity Program. This program, which involves meetings between specially trained health professionals based in medical schools and community clinicians, demonstrates the leadership role that medical schools can play in reducing the incidence of low birthweight.4 7 · County medical society gatherings and meetings of national professional organizations are important sources of information for their members. At the scientific meetings of such groups, the topic of how to strengthen the capacity of prenatal care to reduce low birth- weight should be given increased emphasis. · Public information campaigns can be structured to help focus the attention of health care providers (not just the general public) on important r isks such as nutr itional inadequacies (Chapter 9 ~ . Fourth and finally, it is widely recognized that reimbursement policies and practices exert enormous influence over the content of medical care. Services that are paid for adequately are provided more often than services that are covered inadequately or not at all. Many of the clinical emphases advocated in this report require services for which third party reimbursement is problematic, such as counseling and education to reduce behavioral risks; intensive prenatal services for high-risk women (which may exceed the number of visits covered in set packages of care or include more technologically intensive services); education about pregnancy risks generally, and signs and symptoms of preterm ~ abor specifically; hospitalization for suspected preterm labor or for rest therapy; and ancillary services such as transportation to health care facilities. Tnere Is no single, simple solution to the problem of ensuring adequate reimbursement for such services. Providers such as health maintenance organizations often support them, but most third-party

193 payers do not. It is reasonable to argue that progress would be made, however, if at least the following were to occur: . Both the professional societies of the major maternity care providers and the federal government stress forcefully that adequate prenatal care includes counseling and related support services and that reimbursement should be provided for them. Stipulating such services in a federal definition of comprehensive prenatal care would provide tangible evidence of such a view. · Labor unions, businesses, and other organizations negotiate health insurance benef its that cover more comprehensive prenatal services (suggestions for revising Medicaid reimbursement policies related to prenatal care are in Chapter 7~. · Governmental agencies increase their support of research to define selected classes of services more adequately--both their content and effectiveness. Some reluctance to reimburse for services such as ~ a . a ~ smoking cessation programs is undoubtedly based on understandable confusion on the part of third-party payers as to what the service actually is, who provides it, and what the level of cost-effectiveness and utilization are likely to be. Where such unanswered questions are the clear cause of reluctance to reimburse, research should be pursued to resolve the issues. Research Needs The field of prenatal care is filled with unanswered research questions. In Chapter 6, the evidence that prenatal care decreases the incidence of low birthweight is presented. AS noted in that section, however, prenatal care" is not carefully defined or uniformly practiced. In particular, it is not well understood which components of prenatal care lead to improved pregnancy outcome. Some practice settings offer a package of prenatal care services that is quite extensive--rich In education, screening and diagnostic services, and counseling, and closely linked to other services; other settings offer a less complete set of services . Dif ferences in content may explain a significant part of the variation in the effects of prenatal care r epor ted across studies. The committee has concluded that research on the content of prenatal care should be a high funding priority for foundations, public agencies, and institutions concerned with improving maternal and child health. Research of three kinds is needed: descr iption and analysis of the current composition of prenatal care; assessment of the efficacy and safety of numerous individual components of prenatal care, some of which already are widely employed and others of which are only emerg ing; and

194 evaluation of certain well-defined combinations of specific prenatal interventions designed to meet the widely varied needs and risks among pregnant women. Making major progress in reducing low birthweight, as contrasted to the small but steady improvements in recent years, requires a far more sophisticated understanding of prenatal care content than we have at Present. Over the longer term, the full promise of prenatal care lies In vigorous research to develop ways that can make it even more effective. — — . Describing the Current Content Little is known about what now is included in prenatal care provided in ~ variety of settings, although there are stated standards of what prenatal care should include. For example, ACOG periodically publishes Standards for Obstetric-Gynecologic Services, which outlines both the recommended content and scheduling of prenatal cared These standards are a codification of current understanding of important prenatal problems and their management, as are the Guidelines for Perinatal Care developed jointly by ACOG and the American Academy of Pediatrics .2 Adequate data do not exist, however, on the extent to which these standards are followed In various practice settings. Information is available regarding the brief amount of time obstetricians typically spend with patients in routine prenatal ViSitS48 and about the schedule of prenatal visits followed by some groups of women.~9 However, the extent to which prenatal care providers follow specific ACOG suggestions regarding formalized risk assessment, nutritional status assessment, prenatal education, efforts to reduce smoking In pregnant patients, and related interventions is unknown. The documented brevity of most prenatal visits suggests that many recommended activities are omitted. Accordingly, the committee recommends that: The Assistant Secretary for Health should take the lead in organic ing activities to increase our knowledge of current prenatal care practices. Existing surveys conducted by the National Center for Health Statistics could include a special emphasis on prenatal care content.* Consumer *For example, the National Survey of Family Growth and the Health Interview Survey could provide information on prenatal care from the recipient's point of view; and the National Ambulatory Medical Care Survey (NAMCS) could provide information from the provider side. However, because TALCS surveys only office-based private practice, it will be important to develop ways to survey the content of prenatal care in other settings, such as health departments, hospital outpatient departments, nurse-midwifery services, and various public programs.

195 experience with prenatal care should be analyzed and the professional societies of the major maternity care providers should be consulted about ways to survey their members regarding various content issues. In some instances, it may prove necessary to undertake direc t studies of provider practices . Baseline data assembled from these sources will play a major role in the longer-term effor t to better def ine and improve the content of prenatal care. Research on Individual Care Components Over the course of the study, the committee compiled a long list of r esearch topics centered on specif ic interventions in prenatal care; noted below are topics judged particularly important. Some per tarn to IUGR and others to preterm del ~very. For the sake of simplicity, no distinction ~ s made . C1 inical Topics · improving var ious r isk assessment techniques (such as r isk scor ing systems and assessment of cervical changes} to better identify higher isk patients; · evaluating tocolytic drug therapy in well-defined subpopulatzons, including studies to compare the effectiveness of hydration, rest, and stress reduction with and without tocolysis; · understanding the long-term ef fects on mother and infant of ultrasonography and of tocolytic drugs; and, similarly, studying the efficacy and long-term effects of prophylactic tocolysis in high-risk women; · continuing to refine and evaluate the use of ultrasound imag ing to diagnose pregnancy problems; · assessing the effects of altered schedules of visits for prenatal care (in particular, could ~ow-risk women have fewer prenatal visits than is currently recommended? Do high-risk women need more visits?; · evaluating the efficacy and safety of various prenatal progestational agents; and · assessing the effect on pregnancy outcome of treating a range of genitourinary tract infections and organisms. Behavioral and Environmental Topics · determining the best techniques of educating pregnant women (particularly h~gh-risk women) about self-detection of the early symptoms of preterm labor, and what to do if such symptoms are detected; and evaluating the effects of such education on pregnancy outcome;

196 · developing and evaluating improved techniques, usable in a variety of settings, to help pregnant women reduce or quit smoking; · developing and evaluating more ef fective approaches to reducing alcohol and other substance abuse in pregnant women; · evaluating the effects of stress reducing activities such as bed rest on specific clinical conditions and the outcome of pregnancy generally, including low birthweight; in such studies, it will be ~ mportant to disentangle physical stress and fatigue, psychosocial and emotional stress, and general social policies that may create stress-- designing and evaluating intervention programs in this area will also require greater specificity in both measures and concepts of stress; · developing and evaluating techniques to assess and improve the nutritional status of pregnant women, particularly those with nutritional deficiences; and · expanding and ref. fining the content of childbirth education classes and determining the effects of such instruction on pregnancy outcome . Research on Combinations of Interventions Of equal importance to studying individual components of prenatal care is research to determine the effects of various combinations of interventions. The great variation in risk status among pregnant women suggests that prenatal care should vary significantly in its content for individual women and across populations of women. For example r it is probably the case that the schedule and content of visits for poor, adolescent g ir Is with . numerous r isk factor s such as smok ing and poor nutritional status should be quite different from the care offered middle class, low-risk women. Certainly variations in care already exist, but research to probe the results of carefully constructed combinations of interventions is rare. The prematurity prevention program at the University of California at Los Angeles and the March of Dimes multicenter prevention program described in Appendix C are important steps in this direction. Several other innovative programs are under way or soon to start that attempt to study prenatal care content and effects more care- fully. Some are quite clinical in their orientation, involving small populations and designed to evaluate a few well-defined interventions. Others are more accurately descr ibed as Community based, ~ often involving larger numbers of women and addressing issues of access , f intoning, and linkages among care providers, as well as prenatal care content . Such pro jects include, for example, the Better Babies project in Washington, D.C.; the Florida and North Carolina prematurity prevention activities; the efforts in South Carolina directed at low birthweight prevention; and the program being planned by the Department of Obstetrics and Gynecology of the Albert Einstein College of Medicine in New York. Such programs, if carefully designed to rel ate specific prenatal interventions to well-defined pregnancy outcomes, should contribute

197 over time to improving the capacity of prenatal care to reduce low birthweight. Accordingly, the committee urges that: Both public and pr ivate institutions should supper t studies to assess the effectiveness of well-clef ined combinations of prenatal interventions in reducing low birthweight and improving pregnancy outcomes generally. The prenatal care analyzed in such studies should reflect the highly varied needs of ~ ~ ~ ~ _ individual women and groups. In particular, such studies should assess the merits of different combinations of prenatal interventions for women at elevated risk of prematurity or IUGR. In short, defining and improving the content of prenatal care requires sustained, high-quality research and a commitment of resources adequate to the task. Too often' discussion and research on prenatal care has been oriented to the broad question of whether it improves pregnancy outcome. The appropr late question now is to identify the components and combinations of prenatal care services that are effective In reducing specified risks for well-defined groups of women. Summary Prenatal care as currently offered in the United States has demonstrated its capacity to reduce low birthweight, but emphasizing certain elements of its content could make its contribution even greater. More weight should be placed on careful risk assessment and appropriate intervention to reduce identif fed risks; on early identi- fication and management of threatened preterm labor and IUGR; and on comprehensive patient and provider education. Both the federal government and the major maternity care providers have specif ic roles to play in encouraging these new emphases in prenatal care. A variety of research programs should be developed in both the public and private sectors to increase the ability of prenatal care to reduce low birthweight. Research efforts should focus on three areas: analyses of current prenatal care practices in multiple settings; assessments of the efficacy of individual components of prenatal care; and evaluations of combinations of prenatal interventions specif ically designed to meet the widely varying needs of pregnant women. References and Notes 1. American College of Obstetricians and Gynecologists: Standards for Obstetr ~c~ynecologic Services, Fifth Edition. Washington, D.C., 1982. 2. American Academy of Pediatrics and American College of Obstetricians and Gynecologists: ~~ Guidelines for Per~natal Care. ~ _ lo, Washington, D.C., 1984. Committee to Study the Prevention of Low Birthwe~ght: Risk assessment of low b~rthweight and preterm birth for the individual.

198 Unpublished paper prepared by B Selwyn. Institute of Medicine, 198d . 4. Hall MH, Chng PK, and MacGillvray I: IS routine antenatal care worthwhile? Lancet II: 78-80, 1980. Read MS, Catz C, Grave G. McNellis D, and Warshaw JB: Intrauterine growth retardatzon--identification of research needs and goals. Seminar Per inatol. 8: 2-4, 1984 . National Institutes of Health: Diagnostic Ultrasound Imag ing in Pregnancy. Report of a Consensus Development Conference. NIH No. (PHS) 84-667. Public Health Service. Washington, D.C.: U.S. Government Printing Office, 1984. U.S. General Accounting Office: Better Management and More Resources Needed to Strengthen Federal Efforts to Improve Pregnancy Outcome. Report to the Congress of the United States. GAO No. HRD-80-20. Washington, D.C.: U.S. Government Printing Office, January 21, 1980. Select Panel for the Promotion of Child Health: Better Health for Our Children: A National Strategy. Vol. I. DHHS No. (PHS) 79-55071. Washington, D.C.: U.S. Government Printing Office, 1981 Amer Scan Hospital Association: Health Education: Role and Responsibility of Health Care Institutions. Chicago: Amer ican Hospital Association, 1975 . 0. Select Panel for the Promotion of Child Health: Behavioral aspects of maternal and child health: Natural influences and educational intervention. Prepared by PD Mullen. In Better Health for Our Children: A National Strategy. Vol. IV, pp. 127-188. DHHS No. {PHS) 79-55071. Public Health Service. Washington, D.C.: U.S. Government Printing Office, 1981. Select Panel for the Promotion of Child Health: A child's beginning. Prepared by SS Kessel, JP Rooks, and IM Cushner. In Better Health for Our Children: A National Strategy. Vol. IV, pp. 199-242. DHHS No. (PHS) 79-55071. Public Health Service. Washington, D.C.: U.S. Government Printing Office, 1981. Cogan R: Effects of childbirth preparation. Clin. Obstet. Gynecol. 23:1-14, 1980. See also Perkins ER: The pattern of women's attendance at antenatal classes: IS this good enough? Health Educ. J. 39:3-9, 1980. Davis CD and Marrone FA: An objective evaluation of a prepared childbirth program. Am. J. Obstet. GYnecol. 84 :1196-1206, ~ 962 . 5. 6. 7. 8. Wash ington, D. C .: _ _ 14. Nurses Association of the American College of Obstetricians and Gynecologists (NAACOG): Guidelines for Childbirth Education. Washington, D.C.: NAACOG, 1981. See also: International Childbirth Education Association {ICEA): Position Paper on Planning Comprehensive Maternal and Newborn Services for the Childbearing Years. Minneapolis: ICEA, 1979. Enkin M: Antenatal classes. In Effectiveness and Satisfaction in Antenatal Care, edited by M Enk in and I Chalmers, pp. 151-162. Philadelphia: Spastics International Medical Publications, 1982. 16. Timm M: Prenatal education evaluation. Nurs. Res. 28:338-342, 1979.

199 17. Robitaille Y: The effect of prenatal courses on maternal health behavior and neonatal outcome . Doctoral Dissertation, Department of Ep~demiol ogy and Health, McGill University. Montreal, Canada, 1983 . 18. Sokol Pal, Woolf RB, Rosen MG, and Weingarden K: Risk, antepartum care, and outcome: Impact of a maternity and infant care project. Obstet. Gynecol. 56 :150-156, 1980 . 19 . Barden TP, Peter JB, and Merkatz IR: Ri todr ine hydrocholor ice: A betam~metic agent for use in preterm labor. I. Pharmacology, clinical history, administration, side effects, and safety. Obstet. Gynecol. 56:1-6, 1980. 20. Merkatz IR, Peter JB, and Bar den TP: Ritodrine hydrochloride: A betamimetic agent for use in preterm labor. II. Evidence of efficacy. Obstet. Gynecol. 56:7-12, 1980. 21. Huszar G and Naftolin F: The myometrium and uterine cervix in normal and preterm labor. N. Engl. J. Med. 311:571-581, 1984. 22. Stein ZA and Susser ME: The Dutch famine, 1944/45 and the reproductive process . 1. Effects on s ~ x indices at birth . Pediatr. Res. 9: 70-76, 1975. 23 . Committee on Nutr ition of the Mother and Preschool Child: Nutrition Services In Perinatal Care. Food and Nutrition Board, National Research Council. Washington, D.C.: National Academy Press, 1981. 24. Committee to Study the Prevention of Low Birthweight: Efforts to change smoking and drinking behavior in pregnant women. Unpublished paper by S Wilner. Washington, D.C.: Institute of Medicine, 1984 . 25. Donovan do: Randomized controlled trial of anti-smoking advice in pregnancy. Br . J . Prev. Social Med. 31: 6-12, 1977 . 26 . Sexton M and Hebel JR: A clinical tr ial of change in maternal smoking and its effect on birth weight. JAMA 251:911-915, 1984. 27. Bailey JW, Loeb BE, and Waage G: A randomized trial of smoking intervention during pregnancy. Paper presented at the 111th Annual Meeting , Amer ican Public Health Association, Dallas , Tex ., 1983. 28. Ershoff OH, Aaronson NO, Danaher BG, and Wasserman ErW: Behavioral, health and cost outcomes of an Abased prenatal health education program. Public Health Rep. 98:536-547, 1983. 29. Wilner S. Schoenbaum SC, Palmer RH, and Fountain R: Approaches to intervention programs for pregnant women who smoke. In Proceedings of the Fifth World Conference on Smoking and Health, Winnipeg, Canada, July 1983. 30. Rotelchuck M, Schwartz JB, Anderka MT, and Finison KS: WIC participation and pregnancy outcomes: Massachusetts statewide evaluation project. Am. J. Public Health 74:1086-1092, 1984. 31. Edozien JC, Switzer BR, and Bryan RB: Medical evaluation of the Special Supplemental Food Program for Women, Infants and Children. Am. J. Clin. Nutr. 32: 677-692, 1972. 32. Kennedy ET, Gershoff S. Reed a, and Austin JE: Evaluation of the effect of WIC supplemental feeding on birthweight. J. Am. Dietetic Assoc. 80:220-227, 1982.

200 Metcoff J. Costiloe.P,.Crosby W. Sandstead H. Bodwell CE, and Kennedy E: Nutrition in Pregnancy. Final report submitted to the Food and Nutrition Service, U.S. Department of Agriculture, Washing ton, D.C., 1982. 34. Kotelchuck M and Anderka MT: Massachusetts Special Supplemental Program for Women,.Infants and Children (WIC).Follow-up Study. Final report submitted to U.S. Department of Agriculture, Washington, D.C., 1982. U.S. General Accounting Office: WIC Evaluations Provide Some Favorable But No Conclusive Evidence on the Effects Expected for the Special Supplemental Program for Women, Infants and Children, pp. ii-iv. Report to the Committee on Agriculture, Nutrition, and Forestry, United States Senate. GAO No. PEMD~84-4. Washington, D.C., January 30, 1984. 36. Rush D, Alvir JM, Garbowski Go, Leighton J. and Loan NL: National Evaluation of the Special Supplemental Food Program for Women , Infants and Children (WIC): Review of past studies of health ef feats of the Special Supplemental Food Program for Women, Infants and Children (WIC), p. 103. Submitted to the Office of Analysis and Evaluation, Food and Nutrition Service, Department of Agr iculture. June 30, 1984 . Schram OF: An Analysis of the Effects of WIC. Jefferson City, Ho.: Missouri Department of Public Health, 1983. 38. Caan B: An evaluation of the.effect of supplemental feeding dur ing the interpregnancy interval op.-birth outcomes. November 1984. Unpublished paper cited with permission of the author. Contact Caan at the California State Department of Health Services, Berkeley, Calif. 39. Mora JO, de Pardes B. Wagner M, de Navarro L, Suescun J. Christiansen N. and Herrera MG: Nutritional supplementation and the outcome of pregnancy. I. B~rthweight. Am. J. Clin. Nutr. 32:455-462,.1979. 40. Habicht.~P, Yarborough C, Lechtig A, and Ki ein RE: Relation of maternal supplementary feeding dur ing pregnancy to birthweight and other sociobiological factors. In Proceedings of the Symposium on Nutrition and Fetal Development, edited by M Winick, pp. 127-145. New York: John Wiley & Sons, 1973. 41. Monrad DM and Pelavin SH: Evaluation of the Commodity Supplemental Food Program. Durham, N.C.: NTS Corporation, 1982. 42. Jeffrey RL, Bowes WA Jr, and Delaney JJ: Role of bed rest in twin gestation. Obstet. Gynecol. 43-: 822-826, 1974 . Nuckolls RB, Cassel JC, and Raplan BE: Psychosocial assets, life crisis and prognosis of pregnancy. Am. J. Epidemiology 95: 431-441, 1972 . 44. Herron MA and Dulock BL: Preterm Labor: A Staff Development Program in Perinatal Nursing Care. White Plains, N.Y.: March of Dimes Birth Defects Foundation, 1982. 45. Herron MA, Katz M, and Creasy PR: Evaluation of a preterm birth prevention program: Preliminary report. Obstet. Gynecol. 59: 452-456, 1982 . U.S. Department of Agricu, sure,

201 46. Kamer man SB, Kahn A;T, and Kingston PW: Maternity Policy and Working Women. New York: Columbia University Press, 1983. 47. Mary Lou Moore, Bowman Gray School of Medicine, Winston-Salem, N.C. Personal communication, ~ 984. 48. National Center for Health Statistics: Office Visits by Women: The National Ambulatory Medical Care Survey. Prepared by BE Cypress. Vital and Health Statistics, Ser ies 13, No. 45. DELIS No. (PES) 80-1976. Public Health Service. Washington, D.C.: U.S. Government Pr inting Office, March 1980 . 49. Ressel SS and Kleinman J. Preliminary data from the 1980 National Fatality and Fetal Mortality Follow Back Surveys. National Center for Health Statistics {Rleinman) . Personal communication, 1984.

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Preventing Low Birthweight Get This Book
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Despite recent declines in infant mortality, the rates of low birthweight deliveries in the United States continue to be high. Part I of this volume defines the significance of the problems, presents current data on risk factors and etiology, and reviews recent state and national trends in the incidence of low birthweight among various groups. Part II describes the preventive approaches found most desirable and considers their costs. Research needs are discussed throughout the volume.

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