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

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: = -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.