Weight, height, skinfold thicknesses, circumference measurements, and 72-hour food records were collected from pregnant women (N=51) at four-week intervals between the 12th and 40th weeks of gestation. Subjects were divided Into two groups according to percent standard prepregnant weight for height: overweight > 110% (N=17) and normal weight < 110% (N=28). Changes In weight, skinfold thicknesses and circumference measurements were similar between the two groups during the third trimester (weeks 28 to 40 of gestation). Significant increases in weight (1.58 kg per four weeks) and waist circumference and significant decreases in calf and abdominal skinfold thicknesses are reported. When the second and third trimesters (weeks 12 to 40 of gestation) were considered mean weight gain was 1 .87 kg per four-week interval. Overweight gravidas demonstrated a significantly greater decrease in abdominal skinfold thickness than normal-weight gravidas. The patterns of change over the second and third trimesters were different between the two groups for abdominal, knee, and calf skinfold thickness, hips and thigh circumference, body fat, and percent body fat. Caloric and macronutrient consumption was similar between groups and did not change throughout the second the two and third trimesters. Maternal weight gain was significantly associated with infant birth weight in both groups. / M.S.