Uterine Reaction to Oxytocin and Maternal-Neonatal Outcomes in Inducing Labor: A Retrospective Cohort Study.

BACKGROUND

Previous studies did not investigate the effect of gradually increasing the concentration of low-dose oxytocin on mother and newborn outcomes. The purpose of this study was to look at the relationship between oxytocin responsiveness and outcomes for both mothers and newborns during labor induction.

METHODS

This retrospective cohort study was conducted at Nantong Maternal and Child Health Hospital, and participants were divided into the early reaction to oxytocin group and the later reaction to oxytocin group based on oxytocin response. Primary outcomes included Apgar score at 1 and 5 minutes, umbilical cord artery pH, neonatal intensive care unit admission, and postpartum hemorrhage. Secondary outcomes assessed the duration of labor. Multiple regression models were used to compare maternal and infant outcomes between the two groups.

RESULTS

A total of 1803 participants were finally included in the statistical analysis, with 1083 in the early reaction to oxytocin group and 720 in the later reaction to oxytocin group. After adjusting for potential confounding factors, the risk of a lower 1-minute Apgar score (OR: 1.924, 95% CI: 1.012-3.655), an increased rate of neonatal intensive care unit admission (OR: 2.064, 95% CI: 1.150-3.703), and a higher incidence of postpartum hemorrhage were observed in the later reaction to oxytocin group (OR: 2.342, 95% CI: 1.631-3.361). Additionally, in this group, the first and second phases of labor were seen to be more drawn out (P<0.001, P<0.001).

CONCLUSION

Later reaction to oxytocin was consistently associated with lower 1-minute Apgar scores, an increased number of admissions to neonatal intensive care units, a labor's first and second phases lasting a long time, and an increased occurrence of postpartum hemorrhage. These findings underscore the importance of identifying women who exhibit a delayed response to oxytocin in clinical practice.

TRIAL REGISTRATION: The project was retrospectively registered with the Chinese Clinical Trial Registry (TRN: ChiCTR2100047137; 08/06/2021).