Ventura (1994), found that unmarried mothers were more likely than married mothers to gain less than 7.3 kg during pregnancy. Olsen and Strawderman (2003) found in a cohort of 622 healthy adult women that 38 percent of married women had gained above the IOM (1990) guidelines, compared to 42 percent of women who were separated or divorced, and 48 percent of single women. They also found that 21 percent of married women had gained below the IOM (1990) guidelines, compared to 23 percent for single women and 29 percent for women who were separated or divorced. Thus married women were more likely to gain within the IOM (1990) recommended weight gain range than single or separated/divorced women.

The committee identified only two studies pertaining to the relationship between partner support and GWG. In the first, Dipietro et al. (2003) examined the influences of partner support on attitudes or behaviors toward GWG. In a cross-sectional study of 130 women with low-risk pregnancies, they found that partner support was associated with negative pregnancy body image, but not with attitudes or behaviors toward GWG. Siega-Riz and Hobel (1997) evaluated a clinic sample of 4,791 Hispanic women in Los Angeles and found that receiving financial support from the infant’s father was significantly associated with decreased risk of poor GWG for overweight and obese women, but not for underweight or normal weight women.

Again, the committee only identified two studies pertaining to the influence of family support on GWG. In a sample of 99 pregnant adolescents, Stevens-Simon et al. (1993b) found that attitudes toward GWG were directly related to their perceived family support; negative weight gain attitudes were most common among heavier adolescents, depressed adolescents, and adolescents who did not perceive their families as supportive. In a study of 46 pregnant Mexican American adolescents, Gutierrez (1999) reported that the most powerful factors contributing to good food practices during pregnancy were maternal concern about the well-being of the infant, role of motherhood, and family support system; the investigators did not report on the contribution of family support to either GWG attitude or actual GWG.

The following discussion summarizes the committee’s review of the evidence on several different types of maternal factors and their potential impact on GWG. This evidence includes sociodemographic factors, such