Body composition, dietary intake, and energy expenditure in pregnant women

Abstract

Normal weight (NW) and overweight (OW) pregnant women were compared longitudinally regarding weight gain, pregnancy outcome variables, body composition, energy intake, and activity patterns. Subjects were measured during gestational weeks 12-13, 25-26, 37-38, and 6-12 wk postpartum (n=5 NW, 4 OW for 12-13 wk measurement; n=9 NW, 7 OW for other measurement periods). Self-reported prepregnancy weights were 58.6 ± 5.3 and 81.2 ± 14.0 kg for NW and OW groups, respectively. Prepregnancy body mass indices were 21.4 ± 1.6 for NW subjects and 28.7 ± 3.6 for OW women. No differences were observed between groups for any aspect of pregnancy outcome. Mean weight gains were 14.7 ± 3.6 and 14.5 ± 9.1 for NW and OW groups, respectively. Maternal weight gain was correlated neither with energy intake nor infant birth weight. Differences among skinfold thickness at the various measurement periods were not statistically significant. In the NW group, sum of the triceps, biceps, and subscapular skinfold thicknesses tended to increase substantially in the 2nd trimester, with a smaller increase in the 3rd trimester, and to decrease postpartum. For the OW group, the tendency was for the sum of the skinfolds to increase slightly in the 2nd trimester and decrease in late pregnancy. Percentage body fat and body fat mass estimated by underwater weighing were higher (p < 0.001) at all measurement periods than estimates based on skinfold measurements. Body fat percentages changed significantly over the measurement periods. Body fat mass, based on skinfold measurements, increased significantly between wk 12-13 and 25-2 6. Body fat mass tended to increase slightly between wk 25-26 and 37-38 for the NW group and decline slightly for the OW subjects. Neither energy intake nor activity patterns differed significantly between groups or among time periods. The tendency was for the OW women to be more sedentary than the NW group. The study represents the first report of a longitudinal comparison of NW and OW pregnant women. Trends indicate that there may be differences between responses of NW and OW women with regard to energy balance during pregnancy.