Associations Between Duration of Second Stage of Labor and Lactation Outcomes in the Immediate Postpartum Period

Background: A longer second stage of labor has been associated with increased likelihood of perinatal morbidity and mortality, but associations with the initiation of early and exclusive breastfeeding has not been explored. Research Aims: The objective of this study was to examine the relationship between second stage of labor duration and lactation outcomes in the first 7 days after birth. Methods: A secondary cross-sectional analysis was performed using electronic health record and survey data from a subset of primiparous participants from a longitudinal randomized control trial. Participants were included in the analysis if they intended to exclusively or near-exclusively breastfeed, had a vaginal birth, and they and their infants were discharged in the first 7 days after birth. Lactation outcome measures were timing of the first feed after birth, infant formula feeding frequency, direct chest/breastfeeding frequency during the 24 hours before discharge, and delayed onset of Lactogenesis II. Negative binomial, Poisson, and binary logistic regression models were applied for analyses. Results: The final cohort included 163 participants. The mean second stage of labor duration was 1.58 hours. Nearly half (46%) of participants used infant formula during hospitalization but second stage of labor duration was not significantly associated with the measured lactation outcomes. Conclusion: Longer second stage of labor duration was not associated with the defined lactation outcomes, thus did not impair attainment of early and exclusive breastfeeding in the first 7 days after birth.