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15 of evolving concepts of risk should focus on both the nature and the magni- tude of the risk. Stress, various infections, inadequate plasma volume expan- sion, uterine irritability, and the other, somewhat speculative risk factors noted earlier are potentially very important in the development of Tow birthweight and merit careful study. For both known and less certain risk factors, efforts should be made to distinguish risks for very Tow birthweight (1,500 grams or less) from risks for moderately Tow birthweight (1,501 to 2,500 grams) at various gestational ages. These subcategories of low birthweight may be associated with differ- ent causal mechanisms and health consequences and therefore may require different preventive interventions. Improved understanding of low birthweight also will depend on more timely data analysis and reporting (particularly of vital statistics data) and on greater uniformity of reporting procedures and terminology across states. in aciclition, high priority should be given to more detailed studies of selected cohorts of pregnant women, because vital record data alone do not provide sufficient information on important aspects of maternal behavior (such as smoking) and pregnancy history or on the content of prenatal care. All of these efforts will contribute to improvements in the science of risk assessment, among other benefits. Additional ways to strengthen the impact of risk assessment include: establishing more uniform outcome definitions to allow comparisons among risk assessment systems, testing of various risk assessment methods in the same population, testing of indiviclual risk as- sessment instruments on populations other than those contributing to their development, and designing systems to permit some degree of in- dividualization of the risk score. Opportunities for Prevention Against a background of the data summarized briefly above on trends in low birthweight and on associated causes and risks, the committee outlined several approaches to reducing the occurrence of low birthweight in infants. The next several sections describe those strategies found most promising and feasible. PLANNING FOR PREGNANCY Numerous opportunities exist before pregnancy to reduce the incidience of low birthweight, yet these are often overlooked in favor of interventions cluring pregnancy. In a fundamental sense, healthy pregnancies begin be- fore conception. Therefore, the committee emphasizes the importance of prepregnancy risk identification, counseling, and risk reduction; health edu- cation related to pregnancy outcome generally and to low birthweight in particular; and full availability of family planning services, especially for low-income women and adolescents. Prepregnancy Risk identification and Reduction Among the risk factors that can be recognized and addressed before pregnancy are certain maternal chronic illnesses, smoking, moderate-to

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16 heavy alcohol use, inadequate weight for height, poor nutritional status, susceptibility to rubella and other infectious agents, age (under 17 and over 34), the possibility of a very short interval between pregnancies, and high parity. For some of these factors, reducing the risk before conception may offer more protection than doing so once pregnancy has been established. For example, the famine studies following World War I} demonstrated the im- portance of adequate nutritional status during the period immediately before pregnancy. 13 Similarly, some chronic maternal illness such as hypertension or diabetes presents a less serious risk to both mother and fetus if the condition is adequately controlled before pregnancy. Also, reducing high levels of alcohol and tobacco consumption before conception may exert more of a protective effect with regard to Tow birthweight than reduction during pregnancy. Accordingly, some experts have suggested that more attention be given to preprecnanc~ counseling aimed at detecting risk factors and in,terv~n,in~ 1 1 0 J ~ ~ ~ where possible, to reduce them. Prepregnancy counseling is especially im- portant for women who already have experienced a poor pregnancy out- come. As noted earlier, when a woman has had a preterm birth or a baby with TUGR, the risk of the same problem in subsequent pregnancies increases substantially. Health care professionals should pay special attention to risk factor identification and reduction in these women. Prepregnancy consultations should be available from a variety of profes- sionals in different settings. Obstetricians and gynecologists, nurses and nurse-midwives, family planning personnel, and primary care providers generally should be made aware of the importance of prepregnancy risk identification. Pediatricians, in particular, have an important role to play. For example, in working with families having a child born at low birthweight, pediatricians and related health care providers can counsel about risk reduc- tion if a future pregnancy is anticipated. Also, in caring for adolescent girls, pediatricians and other primary care providers have an opportunity to re- duce selected risks (for example, by immunizing against rubella) and to introduce basic concepts of planning for pregnancy. Realizing the benefits of prepregnancy risk identification will require widespread education of both health care professionals and the general public about this concept. Success also will depend on the willingness of third-party payers to reimburse for such services and on the availability of health resources to manage problems once they have been identified. Fur- ther research is needed to define these prepregnancy services further and to determine their effectiveness. Enlarging the Content of Health Education A second strategy available before pregnancy involves health education related to reproduction. Education about reproduction, contraception, preg- nancy, and associated topics already is provided in a variety of ways: through public information campaigns; in school-based classes, group ses- sions, lectures, and related printed materials; and in various health care settings. To increase the impact of these education programs on the problem

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17 of low birthweight, they should be expanded to include the following six topics: 1. a description of the principal factors that place a woman at risk of poor pregnancy outcome, including low birthweight; 2. the general concept of reducing specific risks before conception and the advisability of counseling before pregnancy to identify and reduce risks associated with low birthweight; 3. the importance of early pregnancy diagnosis and of early, regular prenatal care (including how to obtain such services); 4. the importance of immunizing against rubella and of identifying other infection-related risks to the fetus; 5. the value of altering behavior to reduce a range of risks associated with low birthweight, including smoking, poor nutrition, and moclerate-to-heavy alcohol consumption; and 6. the heightened vulnerability of the fetus to environmental and be- havioral dangers in the early weeks of pregnancy, often before pregnancy is suspected or diagnosed, and therefore the need to avoid x-rays, alcohol and drug use, selected toxic substances, and similar threats in the first 3 months of pregnancy. These health education themes should be included in a variety of health care settings, including family planning clinics where many women of reproductive age receive care. National organizations of family planning providers should promote the use of educational materials encompassing these themes, particularly for their clients who are considering becoming pregnant. Private practitioners also should offer comprehensive health edu- cation related to reproduction, incorporating these same topics. Of equal importance are the sex education and family life education curric- ula and teaching materials of schools. Although these issues may be dis- cussed in some settings, the little information available on school-based health education suggests that they are of low priority. The Role of Family Planning Family planning services should be an integral part of overall strategies to reduce the incidence of low birthweight. Several studies suggest that family planning has made a considerable contribution to reducing the infant mortal- ity rate in the United States over the past 20 years and has also played a role in the gradual decrease in the rate of Tow birthweight. Family planning helps to decrease the occurrence of low birthweight by reducing the number of births to women with a variety of high-risk character- istics, including extreme youth or age, a large number of previous births, chronic severe hypertension, severe heart and kidney diseases, and other risk conditions. These services also reduce the probabilities of a low-weight birth by increaseing the interval between births for many women; an interval of less than 6 months is associated with a sharply elevated risk of low birthweight. The committee explored the concept that family planning also reduces low birthweight by increasing the proportion of pregnancies that are intended