Multivariate Analysis of Factors Associated with Feeding Mother's Own Milk at Discharge in Preterm Infants: A Retrospective Cohort Study.

Objective:  This study aimed to develop a predictive model of feeding mother's own milk (MOM) at discharge using social determinants of health (SDOH), maternal and neonatal factors after deliveries at <33 weeks of gestational age (GA), or birth weight <1,500 g.

Study design:  Secondary analysis of a retrospective cohort in an inner-city hospital before (Epoch-1, 2018-2019) and after (Epoch-2, 2020-2021) implementing a donor human milk (DHM) program.

Results:  Among 986 neonates, 495 were born in Epoch-1 (320 Hispanic White, 142 Non-Hispanic Black, and 33 Other) and 491 in Epoch-2 (327, 137, and 27, respectively). Feeding any MOM was less frequent in infants of non-Hispanic Black mothers than in those of Hispanic mothers (p < 0.05) but did not change with epoch (p = 0.46). Among infants who received any MOM, continued feeding MOM to the time of discharge was less frequent in infants of non-Hispanic Black mothers versus those of Hispanic mothers, 94/237 (40%) versus 339/595 (57%; p < 0.05), respectively. In multivariate analysis including SDOH and maternal variables, the odds of feeding MOM at discharge were lower with SDOH including neighborhoods with higher poverty levels, multiparity, substance use disorder, non-Hispanic Black versus Hispanic and young maternal age and increased with GA but did not change after implementing DHM. The predictive model including SDOH, maternal and early neonatal variables had good discrimination (area under the curve 0.85) and calibration and was internally validated. It showed the odds of feeding MOM at discharge were lower in infants of non-Hispanic Black mothers and with feeding DHM, higher need for respiratory support and later initiation of feeding MOM.

Conclusion:  Feeding MOM at discharge was associated with SDOH, and maternal and neonatal factors but did not change after implementing DHM. Disparity in feeding MOM at discharge was explained by less frequent initiation and shorter duration of feeding MOM but not by later initiation of feeding MOM.

Key points: · In this cohort study of preterm infants, factors of feeding MOM at discharge included (1) SDOH; (2) postnatal age at initiation of feeding MOM; and (3) maternal and neonatal factors.. · Feeding MOM at the time of discharge was less frequent in infants of non-Hispanic Black mothers versus those of Hispanic mothers.. · Disparity in feeding MOM at discharge was explained by less frequent initiation and shorter duration of MOM feeding but not by later postnatal age at initiation of feeding MOM..