Milk Volume Outcomes in Pump-Dependent Mothers of Critically Ill Infants

Mother's own milk improves health outcomes in infants of all gestational ages. Although pump-dependent mothers of extremely premature infants are at risk of insufficient milk production, whether mother's milk production is impacted by gestational age and pump dependency in mothers of more mature critically ill infants is unknown.

To determine whether there is a relationship between gestational age, milk production, and time to secretory activation in mothers delivering a critically ill infant.

A convenience sample of 136 pump-dependent mothers whose infants were admitted to the neonatal intensive care unit was enrolled between 2013 and 2016 as part of a quality improvement project. Group 1 (early preterm) delivered infants at 30 to 33 weeks of gestation (n = 41), group 2 (late preterm) 34 to 36 weeks (n = 48), and group 3 (term) 37 weeks and more (n = 47). Milk volume on days 1 to 7 was measured by weighing each vial of expressed milk and compared using general linear mixed-model analysis. Time to the onset of secretory activation was compared using censored regression analysis.

Main effect for gestational age controlling for day was statistically significant (P = .0234). The early preterm group produced more milk over the 7-day study than the term (P = .01) and late preterm (P = .02) groups. The early preterm group achieved secretory activation earlier than the late preterm group (adjusted P = .039).

Pump-dependent mothers of all infants admitted to the neonatal intensive care unit may be at risk of inadequate milk production and delayed secretory activation and may therefore benefit from early milk production monitoring and lactation support.

Further studies should examine targeted interventions to increase milk production in pump-dependent mothers.