Associations of Gestational Weight Gain With Short- and Longer-Term Maternal and Child Health Outcomes

Abstract

Several studies have reported that changes in maternal gestational weight gain during pregnancy are associated with increased or decreased risk of 5 short- and longer-term adverse maternal or neonatal outcomes: small-for-gestational-age (SGA) birth, large-for-gestational-age (LGA) birth, preterm birth, maternal postpartum weight retention, or child obesity. A few prior studies examined multiple outcomes at the time of birth and reported that the maternal weight gain associated with the lowest-risk may be somewhat lower than current recommendations, especially for obese women. No previous studies, however, have simultaneously investigated both short- and longer-term outcomes, quantitatively summed the predictive prevalence of several outcomes, and examined the effect of different outcome weightings on results. This study examined the relationship between different maternal weight gains during pregnancy and the risk of adverse outcomes including SGA, LGA, preterm delivery, substantial maternal postpartum weight retention, and child obesity in 2,012 mother-child pairs enrolled in Project Viva, a longitudinal pre-birth cohort study. Predicted probabilities were generated for each of the 5 outcomes within each maternal BMI stratum by varying gestational weight gain across the observed range within that stratum. For each BMI category, the maternal weight gain associated with the lowest average predicted probability of the 5 adverse outcomes was determined. Normal weight was defined as a BMI of 18.5 to 24.9 kg/m 2 , overweight as a BMI of 25.0 to 29.9 kg/m 2 , and obesity as a BMI of 30.0 kg/m 2 or greater. Among all women, the mean rate of total gestational weight gain was 0.39 kg/week (standard deviation, 0.14; range: 0.19 to 1.03). The prevalence of SGA and LGA was 6% and 14%, respectively. The prevalence of preterm delivery was 7% and that of substantial postpartum weight retention and child obesity was 16% and 10%, respectively. The lowest predicted prevalence of all 5 adverse outcomes was found among normal-weight women with a gestational gain of 0.28 kg/week, overweight women with a loss of 0.03 kg/week, and obese women with a loss of 0.19 kg/week. Estimates of the maternal weight gain associated with the lowest risk varied modestly for normal-weight and overweight women after adjustment for maternal characteristics and different outcome weights. In contrast, for obese women the maternal weight gain associated with the lowest risk in all models was weight loss. The investigators conclude from these findings that that gestational weight gain recommendations for overweight and obese women should be lowered.