(183) Continuous versus Intermittent Oxytocin Induction in Nulliparous: A Randomized Controlled Trial

Thursday, February 9, 2023

10:30 AM – 12:00 PM

Objective: To assess whether the mode of oxytocin infusion used for labor induction has an effect on the chances for a delivery within 24 hours.

Study Design: We performed a randomized controlled trial at a single tertiary medical center, form January 2020 until June 2022. Nulliparous singleton pregnancies with vertex presentation and Bishop score > 6 (either spontaneous or following surgical balloon ripening) were randomly assigned into one of the following groups: continuous oxytocin (16-hour oxytocin infusion followed by 4-hour break) or intermittent oxytocin (8-hour oxytocin followed by 4 hours breaks) infusion, attempted to be repeated until delivery. In both groups infusion was halted whenever maternal or fetal compromise appeared. Primary outcome was vaginal delivery within 24 hours from first infusion and secondary outcome included time to delivery, mode of delivery, and additional maternal and neonatal outcomes. We calculated that 72 women per group provide 80% power to identify 20% difference in the primary outcome.

Results: 155 nulliparous were included; 72 in the continuous group and 81 in the intermittent group. The total oxytocin infusion time was similar between the groups. Women of the continuous group were more likely to deliver vaginally within 24 hours from oxytocin initiation (79.73% vs. 62.96%, p< 0.05), with a shorter oxytocin-to-delivery time interval, compared with women of the intermittent group (9.3+3.7 vs. 21±11.7 hours, p< 0.001). Time from rupture membranes to delivery was shorter (9.3 ± 3.7 hours vs. 21 ± 11.7 hours, p< 0.0001) and chorioamnionitis was less frequent (9.46% vs. 21%, p< 0.05) in the continuous oxytocin group compared with the intermittent group. There were no cases of hyponatremia due to long oxytocin infusion, or any other difference in neonatal outcome. Greater stratification was noted among the women receiving continuous oxytocin infusion.

Conclusion: We recommend to use continuous infusion of oxytocin for labor induction in nulliparous since it shortens labor time, decreases the rate of chorioamnionitis, and improves maternal satisfaction.

Primary & Presenting Author(s)

Gal Bachar, MD (she/her/hers)
Rambam Healthcare Campus
Haifa, Israel

Coauthor(s)

HA
Hiba Abu-Rass, MD
Rambam Medical Health Campus
Haifa, Israel, Israel
Roy Lauterbach, MD
Department of Obstetrics and Gynecology, Mount Sinai Hospital, Toronto, Canada
Toronto, Ontario, Canada
Naama Farago, MD (she/her/hers)
Rambam Medical Health Campus
Haifa, Israel
Naphtali Justman, MD, MPH
Rambam Health Care Campus
Haifa, Israel, Israel
NK
Nizar Khatib, MD
Rambam Healthcare Campus
Acre, Hefa, Israel
Yaniv Zipori, MD
Rambam Healthcare Campus
Binyamina, HaZafon, Israel
ZW
Zeev Weiner, MD
Rambam Health Care Campus
Haifa, Israel, Israel
Dana Vitner, MD
Rambam Health Care Campus