(HRSA), Department of Health and Human Services (HHS), to examine issues relating to maternal weight gain that had been published in the IOM (1990) report. The goal of this group was to determine whether new research provided a basis for practitioners to change guidance for GWG and recommend future directions for research, training, and/or other programmatic initiatives. The group concluded that formal revision of the IOM (1990) weight gain recommendations was not yet warranted; however, reservations were expressed that the recommendations for African American women, young adolescents, and women of short stature were too specific (Suitor, 1997).
Since publication of the IOM reports, Nutrition During Pregnancy (1990), Nutrition During Lactation (1991), and Nutrition During Pregnancy and Lactation: An Implementation Guide (1992), the population of U.S. women of childbearing age has become more diverse. Although low birth weight remains a significant concern during pregnancy, new health concerns have emerged. These include the greater prevalence of women who are overweight or obese entering pregnancy, which puts them at high risk for pregnancy complications. For example, data from the 2003-2004 round of the National Health and Nutrition Examination Survey (NHANES) show that 28.9 percent of women of reproductive age (20-39 years old) were obese (BMI ≥ 30 kg/m2) and 8.0 percent were extremely obese (BMI ≥ 40 kg/m2) (Ogden et al., 2006). Additionally, women are becoming pregnant at an older age and enter pregnancy with chronic conditions such as type 2 diabetes, which also puts them at risk for pregnancy complications and may lead to increased morbidity during their post-pregnancy years (Cleary-Goldman et al., 2005; Joseph et al., 2005; Delpisheh et al., 2008).
Also since publication of the IOM (1990) report and the subsequent 1991 and 1992 reports, research on GWG has demonstrated that weight patterns (underweight and overweight) and total weight gain have short-and long-term consequences for the health of the mother. For example, prepregnancy BMI above normal values (19.8-26 kg/m2) is associated with preeclampsia, gestational diabetes mellitus (GDM), cesarean delivery (Doherty et al., 2006; Abenhaim et al., 2007), and failure to initiate and sustain breastfeeding (Hilson et al., 1997; Li et al., 2003; Kugyelka et al., 2004). Increased maternal BMI and GWG have also been associated with higher fat mass in infants and subsequent overweight in children (Hillier et al., 2007; Oken et al., 2007).
Collectively, these trends (e.g., the greater prevalence of overweight and obese women entering pregnancy) and newer research (e.g., on the consequences of excess GWG) have prompted new concern about the appropriateness of existing guidelines for GWG and whether the guidelines support optimal outcomes for mother, infant, and child. Specifically there have been concerns about the implications of the IOM (1990) recommen-