laid the foundation for work over the next two decades, and in 1974, the U.S. Department of Agriculture established the Special Supplemental Food Program for Women, Infants, and Children to address the needs of women and children at nutritional risk.
In 1990 the Institute of Medicine (IOM) report Nutrition During Pregnancy recommended guidelines for weight gain during pregnancy based on prepregnancy maternal body mass index (BMI). Two other reports quickly followed: Nutrition During Lactation (1991) and Nutrition During Pregnancy and Lactation: An Implementation Guide (1992).
By this time, the Maternal and Child Health Bureau of the U.S. Department of Health and Human Services had also begun to address concerns about maternal weight gain. And in 1998, the National Heart, Lung, and Blood Institute (NHLBI) released its own classification of overweight and obesity by BMI (National Heart, Lung, and Blood Institute, 1998). The NHLBI classifications differed slightly from the 1990 IOM maternal BMI criteria. However, a common stimulus for all of these earlier efforts was the incidence of low birth weight deliveries, which was in part attributed to insufficient nutrition and insufficient weight gain during pregnancy.
Since publication of the 1990 IOM recommendations for weight gain during pregnancy, tremendous changes have occurred in the demographic and epidemiological profile of women experiencing pregnancy. More women entering pregnancy are either overweight or obese, and more women are entering their pregnancies with chronic conditions that lead to increased morbidity during their postpregnancy years. High rates of overweight and obesity are especially common in minority populations that may be already at risk for poor maternal and child health outcomes. Collectively, these trends have prompted concern about the adequacy of existing guidelines for weight gain during pregnancy, particularly for women who are overweight, underweight, short in stature, or adolescents.
Despite the availability of the IOM recommendations and an effort to publicize their availability, their use and compliance are not understood. As researchers have begun to address some of the issues raised in the 1990 IOM report, gaps in knowledge have emerged, even as additional data are collected and reported.
This convergence of factors prompted the NRC and the IOM to organize a workshop on maternal weight gain (before, during, and after pregnancy) and its influence on maternal and child health. With support from the Maternal and Child Health Bureau in the U.S. Department of Health and Human Services, the NRC-IOM Board on Children, Youth, and Families, in collaboration with the IOM Food and Nutrition Board, convened a committee of experts at a day and a half workshop in May 2006 to examine the current state of knowledge and highlight key observations that could form the basis for future study and deliberations regarding