Outcome of Inducing Labor in Pregnancies with Suspected Fetal Growth Restriction: Oxytocin Discontinuation during the Active Phase of Labor versus Conventional Management.

Objective: Although fetal growth restriction (FGR) is associated with an increased risk of cesarean delivery during induced labor, there is limited evidence to guide labor management. This study aimed to investigate the prognosis of induced labor in pregnancies with suspected FGR and whether oxytocin discontinuation during the active phase of labor affects maternal and neonatal outcomes.

Study Design: This retrospective cohort study investigated singleton pregnancies with vertex presentation and indications for labor induction owing to FGR after 34.0 weeks of gestation at Osaka University Hospital. From January 2010 to December 2013, women were conventionally managed, and oxytocin was continued until delivery unless there was an indication for discontinuation (conventional management group). From January 2013 to December 2020, oxytocin was routinely discontinued, or the dose was reduced at the beginning of the active phase of labor (oxytocin discontinuation group).

Results: A total of 161 women (conventional management group,  = 74; oxytocin discontinuation group,  = 87) were included. After the active phase of induced labor, the total incidence of cesarean delivery was very low (3.1%), and the duration was short (173 ± 145 minutes). Oxytocin discontinuation was associated with lower cesarean delivery (1.1 vs. 5.4%;  = 0.12) and uterine tachysystole (9.8 vs. 23.0%;  = 0.08) rates and longer duration of the second stage of labor (mean: 56.5 ± 90 vs. 34.2 ± 45 minutes;  = 0.08) than conventional management; however, the difference was not significant. The other maternal and neonatal outcomes, including postpartum hemorrhage, did not also significantly differ between them.

Conclusion: After the active phase of induced labor for suspected FGR, the risk of cesarean delivery is low, and the high incidence of uterine tachysystole and rapid labor progression should be considered cautiously. Oxytocin can be safely discontinued during the active phase of labor in women undergoing labor induction for FGR without an increased risk of cesarean delivery or other unfavorable outcomes.

Key Points: · The cesarean delivery rate was low after the active phase.. · The labor progress after the active phase was rapid.. · Oxytocin can be safely discontinued during the active phase..