Factors associated with duration of breastfeeding in women giving birth for the first time.

Objective: To examine maternal, psychosocial, and pregnancy factors associated with breastfeeding for at least 6 months in those giving birth for the first time.

Methods: We performed a planned secondary analysis of an observational cohort study of 5249 women giving birth for the first time. Women were contacted at least 6 months after delivery and provided information regarding breastfeeding initiation, duration, and exclusivity. Maternal demographics, psychosocial measures, and delivery methods were compared by breastfeeding groups.

Results: 4712 (89.8%) of the women breastfed at some point, with 2739 (58.2%) breastfeeding for at least 6 months. Of those who breastfed, 1161 (24.7% of the entire cohort), breastfed exclusively for at least 6 months. In the multivariable model among those who ever breastfed, not smoking in the month prior to delivery (adjusted odds ratio [aOR] 2.04, 95%CI 1.19-3.45), having a Master's degree of higher (aOR 1.89, 95%CI 1.51-2.36), having a planned pregnancy (aOR 1.48, 95%CI 1.27-1.73), older age (aOR 1.02, 95% CI, 1.01-1.04), lower BMI (aOR 0.96 95% CI 0.95-0.97), and having less anxiety measured during pregnancy (aOR 0.990, 95%CI 0.983-0.998) were associated with breastfeeding for at least 6 months. Compared to non-Hispanic White women, Hispanic women, while being more likely to breastfeed initially (aOR 1.40, 95%CI 1.02-1.92), were less likely to breastfeed for 6 months (aOR 0.72, 95%CI 0.59-0.88). While non-Hispanic Black women were less likely than non-Hispanic White women to initiate breastfeeding (aOR 0.68, 95%CI 0.51-0.90), the odds of non-Hispanic Black women of continuing to breastfeed for at least 6 months was similar to non-Hispanic White women (aOR 0.92, 95%CI 0.71-1.19).

Conclusions: In this cohort of women giving birth for the first time, duration of breastfeeding was associated with several characteristics which highlight groups at greater risk of not breastfeeding as long as currently recommended.

Trial Registration: NCT01322529 (nuMoM2b) and NCT02231398 (nuMoM2b-Heart Health).