Lactation, seasonality, and mother's postpartum weight change in Bangladesh: An analysis of maternal depletion

Longitudinally collected data from rural Bangladesh was used to investigate the effects of lactation, reproductive patterns, and seasonality on maternal weight and postpartum weight change. Results of multivariate analyses demonstrate that weight change exhibits a strong seasonal pattern, with losses in winter (December through March) and the rainy season (July through November) and gains in other months. The rate of weight loss peaks between 5 and 9 months postpartum, declines to near zero by 16 months postpartum, and becomes positive thereafter. However, season and duration interact, so that women who reach the stage of most intensive nutritional demand at a time of low food supply relative to energy output lose considerably more weight than women who reach that stage when food supplies are more adequate. Currently lactating women lose weight more rapidly than nonlactating women. Weight loss is slower among women with low initial weight. Prior reproductive patterns are associated with both weight at the time of conception and weight gain during pregnancy, which together determine weight at the beginning of the lactation interval. Each additional birth is associated with a decrease of 280 g in weight at conception, whereas interpregnancy intervals of < 18 months are associated with an 800-g deficit at the time of that conception compared to longer intervals. Weight gain during pregnancy is greater among women with high parity, short interpregnancy intervals, and lower weight at conception, but not enough to compensate for the prepregnancy deficit.