Effects of breastfeeding on weight loss and recovery of pregestational weight in adolescent and adult mothers.

Background: Exclusive breastfeeding (EBF) in adolescent mothers has been associated with greater postpartum maternal weight loss.

Objective: To assess the associations between EBF and weight loss in adolescent and adult mothers and between EBF and weight and length gain of their children.

Methods: A cohort of 68 adolescent mothers (15 to 19 years), 64 adult mothers (20 to 29 years), and their infants were studied. Anthropometric measurements were performed at 15, 90, 180, and 365 days postpartum in the mothers and children. EBF was defined as consumption of human milk without supplementation of any type (water, juice, nonhuman milk, or food) for 4 months.

Results: Sixty-five percent of mothers sustained EBF for 4 months. There were no significant differences in the weight or length of the infants of adolescent and adult mothers at 365 days postpartum. Among infants of adult mothers, there was a significant difference between the weight gain of those were exclusively breastfed and those who were not exclusively breastfed (6,498 +/- 1,060 vs 6,096 +/- 1,035 g, p < .050) at 365 days postpartum, according to the parameters for weight gain and length established by the World Health Organization (WHO). Among both adult and adolescent mothers, those who practiced EBF lost more weight than those who did not practice EBF (-2.9 kg, 95% interquartile range, -5.7 to 0.8 kg, vs -1.8 kg 95% interquartile range -2.8 to 2.2 kg; p = .004). Gestational weight gain, duration of EBF, and recovery menstruation explained 21% of the variance (F = 28.184, p = .001) in change in postpartum maternal weight (in kilograms) from 0 to 365 days postpartum in all mothers. Pregestational weight, duration of EBF, and maternal age were factors that explained 14% (F = 22.759, p = .001) of the change in the weight and length of the infants from 0 to 365 days of life.

Conclusions: EBF in adolescent and adult mothers influences postpartum weight loss and provides adequate infant growth in accordance with the WHO 2006 standards.