Contraception and Breastfeeding at 4 Months Postpartum Among Women Intending to Breastfeed

To estimate the association between postpartum contraception and breastfeeding among women intending to breastfeed.

We analyzed data from the Infant Feeding Practices Study II, a prospective cohort study of U.S. mothers (2005-2007). Among 1,349 women with prenatal intention to breastfeed at least 4 months who reported contraception use 3 months postpartum, we used multivariable logistic regression to estimate odds and predicted probabilities of breastfeeding by contraceptive category. We considered prenatal breastfeeding intention, age, race, education, income, marital status, region, depressive symptoms, parity, and timing of return to work as potential confounders, using standard statistical methods to determine model covariates.

At 3 months postpartum, contraception was reported as follows: 720 (53%) nonhormonal contraceptives (NHCs), 256 (19%) combined hormonal contraceptives (CHCs), 217 (16%) progestin-only pills (POPs), 92 (7%) intrauterine devices, and 64 (5%) depot medroxyprogesterone acetate. Compared with NHCs, adjusted odds ratio (aOR) for any breastfeeding at 4 months postpartum among women using POPs was 3.15 (95% confidence interval [CI] 1.42-7.02), and for women using CHCs aOR was 0.17 (95% CI 0.10-0.29). For women using NHCs, predicted probability of any breastfeeding at 4 months postpartum was 90% (95% CI 85-94); it was 97% (95% CI 92-99) among those using POPs and 61% (95% CI 46-74) among those using CHCs.

In a cohort of women intending to breastfeed at least 4 months, women using POPs were most likely, and women using CHCs were least likely, to achieve their breastfeeding intentions.