35: Early-term Deliveries Are Associated with a Reduced Likelihood of Exclusive Breastfeeding

Higher rates of adverse outcomes have been reported for early term (37’0 to 38’6 weeks) versus full term (≥39’0 weeks) infants, but differences in breastfeeding outcomes have not been systematically evaluated. Breast milk confers short and long term health benefits, and exclusive breastfeeding (EBF) is a widely-used perinatal quality indicator. We sought to determine whether frequency of breastfeeding initiation (BFI) and EBF differed for early term versus at least full term infants and to identify factors associated with these breastfeeding outcomes. This retrospective cohort analysis included participants from two study populations: 743 geographically- and racially-diverse subjects from the Measurement of Maternal Stress Study (MOMS) cohort, and 303 patients from a quality assessment at a hospital-based clinic in Evanston, IL. Participants were included in the analysis if they delivered ≥37 weeks and had no documented contraindications to breastfeeding. BFI and EBF were assessed by reviewing electronic medical records after discharge. Associations of BFI and EBF with gestational age, maternal age, race, parity, mode of delivery, insurance status, and baby NICU admission were assessed via univariate analysis and multivariable logistic regression. Of the 875 women eligible for inclusion, 82.9% initiated breastfeeding and 42.5% had EBF. Although early term birth was not associated with any difference in frequency of BFI (p=0.78), it was associated with significantly lower odds of EBF (unadjusted OR 0.51, 95% CI 0.38-0.68, p<0.001). This association remained (adjusted OR 0.56, 95% CI 0.39-0.80, p=0.002) after adjusting for key covariates, including maternal age, parity, mode of delivery, Medicaid status (p<0.001), race (p<0.001), and maternal smoking during pregnancy (p=0.001). Early term infants were half as likely to be exclusively breastfed as full term infants. These data suggest that women with early term infants may benefit from counseling regarding the potential for breastfeeding difficulties as well as additional breastfeeding support after delivery.