The Impact of Maternal Obesity on Breastfeeding

To compare the rate of any breastfeeding at the time of postpartum hospital discharge between obese women (BMI ≥ 30.00 kg/m(2)) and women with a normal BMI (18.50 to 24.99 kg/m(2)).

We conducted a retrospective cohort study of women with live, singleton pregnancies who delivered in St. John's, Newfoundland and Labrador between 2002 and 2011, using data from the Newfoundland and Labrador provincial perinatal registry. The primary outcome was any breastfeeding at the time of discharge from hospital. Secondary analysis included comparison of breastfeeding rates by class of obesity. We compared additional maternal and neonatal outcomes between women who were breastfeeding at discharge and those who were not. Univariate and multivariate logistic regression analyses were performed, and adjusted odds ratios (aORs) and 95% CIs were calculated.

We included 12 831 women with BMI data available in the study: 8676 were breastfeeding and 4155 were not at the time of postpartum discharge. Obese women were less likely to breastfeed than women with normal weight (60.0% vs. 71.7%) (aOR 0.63; 95% CI 0.55 to 0.71). Multivariate analysis showed a significant effect on the primary outcome of a mother's age (aOR 1.03; 95% CI 1.02 to 1.05), nulliparity (aOR 1.73; 95% CI 1.51 to 1.98), being partnered (aOR 1.57; 95% CI 1.34 to 1.84), working (aOR 1.10; 95% CI 1.02 to 1.19), having higher education (aOR 1.48; 95% CI 1.38 to 1.60), smoking (aOR 0.35; 95% CI 0.29 to 0.43), having gestational diabetes (aOR 0.70; 95% CI 0.5 to 0.92), pre-existing hypertension (aOR 0.58; 95% CI 0.39 to 0.87), gestational hypertension (aOR 0.67; 95% CI 0.55 to 0.82), and undergoing general anaesthesia (aOR 0.41; 95% CI 0.22 to 0.77).

Obesity is an independent risk factor for not breastfeeding at the time of postpartum discharge from hospital. It is important to counsel women on the benefits of breastfeeding, emphasizing these particularly in women with a high pre-pregnancy BMI.