Introduction: Breast milk is the ideal food for infants. However, at 6 months of age, 35 weeks gestational age were compared at nursery discharge and ∼30 days of age. Results: At nursery discharge (n = 499), mean birth weight (±standard deviation [SD]) was greater in the EBF versus N-EBF cohort (3.4 ± 0.4 versus 3.3 ± 0.5 kg, p = 0.01). When compared to the N-EBF cohort, infants in the EBF cohort were significantly more likely to have the following characteristics: (1) vaginal birth; (2) non-Hispanic parents; (3) parents with higher socioeconomic status, and (4) parents who are English-speaking (p < 0.01 for all). Similar findings persisted at 30 days. Non-Hispanic parents were 2 (95% confidence interval [CI]: 1.4-3.3) and 3.5 (95% CI: 1.5-7.9) times more likely to exclusively breastfeed than Hispanic parents at nursery discharge and 30 days, respectively. At nursery discharge, families with a Hispanic mother and non-Hispanic father were more likely to EBF than families with a Hispanic mother and father (odds ratio 2.9, 95% CI: 1.1-7.6). In multivariate model, parental ethnicity was associated with EBF at discharge (p = 0.03) and 30 days (p = 0.02). Conclusion: Paternal ethnicity may influence EBF. Addressing disparities in EBF may warrant investigations into culturally inclusive and family-centered interventions.