To evaluate the association between neonatal intensive care unit (NICU) admission and breastfeeding practices, infant supine sleep positioning, and postnatal smoking among mothers of late preterm infants.

Data from 36 states using the 2000-2013 Pregnancy Risk Assessment Monitoring System were analyzed. χ² tests and 95% CI assessed infant and maternal characteristics and recommended care practices for late preterm infants based on NICU admission after birth. Adjusted prevalence ratios (APR) for breastfeeding initiation and continuation at 10 weeks, supine sleep position, and postnatal smoking were estimated using multivariable logistic regression models, controlling for infant and maternal characteristics. Analyses were weighted and SEs accounted for the complex survey design.

Our sample included 62 494 late preterm infants, representing a weighted population of 1 441 451 late preterm infants. In the adjusted analysis, mothers of late preterm infants admitted to a NICU were more likely to initiate breastfeeding (APR 1.07; 95% CI 1.05-1.09) and place their infants in supine sleep position (1.04; 95% CI 1.01-1.06) than mothers of late preterm infants not admitted to a NICU. There was no significant difference between groups for breastfeeding continuation or postnatal smoking.

Mothers of late preterm infants admitted to a NICU were more likely to initiate breastfeeding and practice supine sleep position than mothers of late preterm infants not admitted to a NICU. Future work should seek to identify the drivers of these differences to develop effective strategies to engage mothers in these health promoting infant care practices.