Prematurity and breastfeeding initiation: A sibling analysis

Studies suggest breastfeeding initiation is less common for premature infants. This association may be confounded by socio-economic characteristics that correlate with the risk of premature birth. We compared premature and term-born children to determine whether prematurity independently predicted likelihood of breastfeeding continuation and duration.

Data were obtained from women ages 15-44 years reporting at least two live pregnancies on the 2011-2017 National Survey of Family Growth. Participants completed a pregnancy and breastfeeding history. Breastfeeding initiation was defined as breastfeeding for at least 1 week, and duration of exclusive breastfeeding was recorded in months. Sibling fixed effects regression models were used to evaluate the impact of prematurity.

Among families with some children who were breastfed and others who were not (n = 2848 children), preterm birth was not associated with breastfeeding initiation (odds ratio = 1.11; P = .468). Among children who were ever breastfed, exclusive breastfeeding lasted 5% fewer months among children born preterm, compared with term-born siblings (incidence rate ratio = 0.95; P = .060).

Using sibling-group analysis to control for confounding, we found no independent association between prematurity and likelihood of breastfeeding initiation. This suggests interventions supporting breastfeeding for premature infants may need to address external barriers to breastfeeding not specifically preterm birth.