Breast-Feeding And Postpartum Maternal Weight Trajectories

Objective: We examined whether breast-feeding, and in particular exclusive breast-feeding, was associated with maternal weight and body composition changes at 4 months postpartum independently of other maternal variables.Design: Prospective longitudinal study. Women were recruited in the first trimester after an ultrasound examination confirmed an ongoing singleton pregnancy. Weight and body composition were measured using advanced bio-electrical impedance analysis at the first antenatal visit and 4 months postpartum. Detailed questionnaires were completed on breast-feeding, socio-economic status, diet and exercise in addition to routine clinical and sociodemographic details.Setting: Large Irish university maternity hospital.Subjects: Women who delivered a baby weighing >= 500 g between November 2012 and March 2014.Results: At the postpartum visit, the mean weight was 70.9 (SD 14.2) kg (n 470) and the mean BMI was 25.9 (SD 5.0) kg/m(2). 'Any breast-feeding' was reported by 65.1 % of women (n 306). Irish nativity (OR = 0.085, P < 0.001), current smoking (OR = 0.385, P = 0.01), relative income poverty (OR = 0.421, P = 0.04) and deprivation (OR = 0.458, P = 0.02) were negatively associated with exclusive breast-feeding. At 4 months postpartum there was no difference in maternal weight change between women who exclusively breast-fed and those who formula-fed (+ 2.0 v. + 1.1 kg, P = 0.13). Women who exclusively breast-fed had a greater increase in percentage body fat at 4 months postpartum compared with women who formula-fed (+ 1.0 v. -0.03 %, P = 0.02), even though their dietary quality was better. Exclusive breast-feeding was not associated with postpartum maternal weight or body fat percentage change after adjusting for other maternal variables.Conclusions: There are many reasons why breast-feeding should be strongly promoted but we found no evidence to support postpartum weight management as an advantage of breast-feeding.