Trajectory of weight changes in the first 6 weeks postpartum

Objective: To determine the trajectory of postpartum weight changes and to examine associations between weight change in the first 6 weeks postpartum and demographic, clinical, psychosocial, and behavioral variables. Design: Prospective, longitudinal design. Setting: Community hospital and university research setting. Participants: 26 low-income women (9 White, 8 Black, and 9 Hispanic) with uncomplicated term pregnancies. Main Outcome Measure: Body mass index measured weekly. Results: Among White women, body mass index decreased significantly for the first 3 weeks of the postpartum period. Black women experienced a significant reduction in body mass index for only the first 2 postpartum weeks. Similarly, the postpartum body mass index decreased for the first 2 weeks for Hispanic women. Prepregnancy body mass index and gestational weight gain each had a significant positive effect on postpartum body mass index. Perception of social support at 4 weeks had a significant positive effect on postpartum body mass index in Black women. Conclusions: The trajectory of weight change was nonlinear with large initial weight losses during the first 2 to 3 weeks postpartum followed by weight plateaus for the remainder of the first 6 weeks postpartum.