her published analyses from the Danish National Birth Cohort (Nohr et al., 2008). She provided two sets of analyses and information on an additional lower and an additional higher category of GWG and replicated her published analyses for obese class I women separately from obese class II and III women. She conducted analogous new analyses for several important subgroups of the population of pregnant women, namely primiparous, short, and young women, as well as smokers (information contributed to the committee in consultation with Nohr [see Appendix G, Part I]). Second, with data from the 1988 National Maternal and Infant Health Survey (NMIHS), Dr. Amy Herring analyzed the association between GWG and outcomes important to the committee separately for white and black women. She also linked the 1988 survey data to its 1991 follow-up and examined the association between GWG and postpartum weight retention. She was unable to examine the long-term weight status of infants born LGA because access to the data could not be obtained in a timely manner (information contributed to the committee in consultation with Herring [see Appendix G, Part II]). Third, Dr. Cheryl Stein analyzed adverse outcomes associated with GWG stratified by racial/ethnic group in the subsample of births during 1995-2003 in New York City for which prepregnant BMI was available (information contributed to the committee in consultation with Stein [see Appendix G, Part III]). The fourth commissioned analysis, described in more detail below, was a quantitative analysis of risk trade-offs between maternal and child health outcomes associated with GWG by Dr. James Hammitt (information contributed to the committee in consultation with Hammitt [see Appendix G, Part IV]).

The committee relied on both standard criteria for evaluating the quality of research studies (such as those provided by the American Academy of Pediatrics, 2004) as well as its expert judgment when evaluating the evidence. It used evidence from the published scientific literature as well as the analyses it commissioned. In the development of its recommendations, the committee evaluated the overall quality of the evidence as well as the balance between benefits and risks. Although the committee relied on the highest level of evidence (randomized controlled trials, and experimental studies in women and animal models), few such experimental studies were available in the literature relevant to the committee’s task. In addition, the committee used data from the general population in those instances in which data on minority populations were unavailable.

Prepregnant BMI Category

After the publication of the IOM (1990) report, the World Health Organization (WHO) held a consultation that developed a categorization of BMI values for adults based on different cutoff points (WHO, 1995). The WHO cutoff points were subsequently endorsed by the National Institutes



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