Effect of Breastfeeding on Weight Retention from One Pregnancy to the Next: Results from the North Carolina WIC Program

Objectives: Pregnancy-related weight retention can contribute to obesity, and breastfeeding may facilitate postpartum weight loss. We investigated the effect of breastfeeding on long-term postpartum weight retention.

Methods: Using data from the North Carolina Special Supplemental Nutrition Program for Women, Infants, and Children (WIC; 1996-2004), weight retention was assessed in women aged 18 years or older who had more than one pregnancy available for analysis (n=32,920). Using multivariable linear regression, the relationship between duration of breastfeeding after the first pregnancy and change in pre-pregnancy weight from the first pregnancy to the second pregnancy was estimated, controlling for demographic and weight-related covariates.

Results: Mean time between pregnancies was 2.8 years (standard deviation (SD) 1.5), and mean weight retention from the first to the second pregnancy was 4.9kg (SD 8.7). In covariate-adjusted analyses, breastfeeding for 20 weeks or more resulted in 0.39kg (standard error (SE) 0.18) less weight retention at the beginning of the second pregnancy relative to no breastfeeding (p=0.025).

Conclusion: In this large, racially diverse sample of low-income women, long-term weight retention was lower among those who breastfed for at least 20 weeks.