The Interaction of Early Exclusive Mother's Milk Feeding and Ethnic Background with Ultimate Feeding Outcomes After Very Preterm Birth

Background: Mothers of very preterm infants (born under 32 weeks' gestation) have specific lactation challenges. There is little literature related to the influences on exclusive maternal milk provision.Method: An observational cohort using prospectively entered clinical data in a single tertiary neonatal unit in the United Kingdom over a 2-year period 2019-2021. There were 112 infants born under 32 weeks' gestation who fulfilled inclusion criteria.Results: Average gestation was 27.9 +/- 2.6 weeks at birth and 37.3 +/- 3.3 at discharge. On day 4 after birth, 29% (31/107) received exclusive maternal milk. At discharge, 54% (60/112) received exclusive maternal milk. Exclusive maternal milk at day 4 was associated with exclusive maternal milk at discharge (adjusted relative risk 2.3, 95% confidence interval 1.5-3.6, p < 0.001). Mothers from "white other," Asian, and mixed/multiple ethnic backgrounds were more likely than white British mothers to give exclusive maternal milk at discharge. This association emerged only after adjustment for exclusive maternal milk at day 4 after birth.Conclusions: The association of minority ethnic background with feeding outcomes that has previously been noted in the United Kingdom general population was also found in this very preterm cohort. The relationship was strengthened after adjustment for exclusive maternal milk at day 4. This may suggest that establishing early milk supply is a universal barrier to later exclusive maternal milk in this population and that once milk supply is established, standard social and cultural experiences come to bear on infant feeding decisions.