Association between Delayed Lactogenesis II and Early Milk Volume among Mothers of Preterm Infants

ABSTRACT

PURPOSE: This study aimed to evaluate the effect of delayed lactogenesis II on early milk volume in mothers expressing milk for their preterm infants. METHODS: 142 mothers with preterm infants participated in a longitudinal cohort study, the milk volumes over 14 days postpartum between mothers with delayed lactogenesis II (≥ 72 hours) and mothers with non-delayed lactogenesis II(< 72 hours) were compared using Wilcoxon's rank sum tests. RESULTS: The prevalence of delayed lactogenesis II among mothers of preterm infants was 36.0% (36/100). There existed negative correlations between the onset of lactogenesis II and the daily milk volumes(r(s) = −0.525~−0.354, p = .002 ~ p < .001). The milk volumes in every 24-hour of the 14 days postpartum in delayed group were significantly less than that in non-delayed group (p = .002 ~ p < .001). After controlling for the covariates, pregnancy-induced hypertension syndrome, delayed expression initiation, shorter daily sleeping time were found to be the risk factors for delayed lactogenesis II. CONCLUSION: Delayed lactogenesis II was associated with lower milk volume in early postpartum period. Women who were at risk for delayed lactogenesis II need targeted interventions and additional support during pregnancy and postpartum.