TY - JOUR
T1 - High-Dose Compared With Standard-Dose Oxytocin Regimens to Augment Labor in Nulliparous Women
T2 - A Randomized Controlled Trial
AU - Son, Moeun
AU - Roy, Archana
AU - Stetson, Bethany T.
AU - Grady, Nancy Tunney
AU - Vanecko, Mary Clare
AU - Bond, Nicole
AU - Swanson, Kate
AU - Grobman, William A.
AU - Miller, Emily S.
AU - Peaceman, Alan M.
N1 - Funding Information:
This trial was funded by a grant awarded by the Friends of Prentice Foundation. The funders of the study had no role in the design and conduct of the study; collection, management, analysis, and interpretation of the data; preparation, review, or approval of the manuscript; or decision to submit the manuscript for publication.
Publisher Copyright:
© 2021 Lippincott Williams and Wilkins. All rights reserved.
PY - 2021/6/1
Y1 - 2021/6/1
N2 - OBJECTIVE:To evaluate whether a high-dose oxytocin regimen reduces the risk for primary cesarean birth and other obstetric morbidities when compared with standard dosing.METHODS:In a double-blind randomized clinical trial of nulliparous women at or beyond 36 weeks of gestation who were undergoing augmentation of labor, participants were assigned to high-dose (initial and incremental rates of 6 milliunits/min) or standard-dose (initial and incremental rates of 2 milliunits/min) oxytocin regimens. The primary outcome was cesarean birth. Prespecified secondary outcomes included labor duration, clinical chorioamnionitis, endometritis, postpartum hemorrhage, Apgar score 3 or less at 5 minutes, umbilical artery acidemia, neonatal intensive care unit admission, perinatal death, and a severe perinatal morbidity composite. A sample size of 501 per group (n=1,002) was planned to detect a 6.6% absolute reduction in rate of the primary outcome, from 20% in the standard-dose group to 13.4% in the high-dose group with 80% power.RESULTS:From September 2015 to September 2020, 1,003 participants were randomized - 502 assigned to high-dose and 501 assigned to standard dosing. The majority of participants were of White race, were married or living as married, and had commercial insurance. Baseline characteristics between groups were similar. The primary outcome occurred in 14.5% of those receiving high-dose compared with 14.4% of those receiving standard-dose oxytocin (relative risk, 1.01; 95% CI 0.75-1.37). The high-dose group had a significantly shorter mean labor duration (9.1 vs 10.5 hours; P<.001), and a significantly lower chorioamnionitis incidence (10.4% vs 15.6%; relative risk, 0.67; 95% CI 0.48-0.92) compared with standard dosing. Umbilical artery acidemia was significantly less frequent in the high-dose group in complete case analysis, but this finding did not persist after multiple imputation (relative risk, 0.55; 95% CI 0.29-1.04). There were no significant differences in other secondary outcomes.CONCLUSION:Among nulliparous participants who were undergoing augmentation of labor, a high-dose oxytocin regimen, compared with standard dosing, did not affect the cesarean birth risk but significantly reduced labor duration and clinical chorioamnionitis frequency without adverse effects on perinatal outcomes.CLINICAL TRIAL REGISTRATION:ClinicalTrials.gov, NCT02487797.
AB - OBJECTIVE:To evaluate whether a high-dose oxytocin regimen reduces the risk for primary cesarean birth and other obstetric morbidities when compared with standard dosing.METHODS:In a double-blind randomized clinical trial of nulliparous women at or beyond 36 weeks of gestation who were undergoing augmentation of labor, participants were assigned to high-dose (initial and incremental rates of 6 milliunits/min) or standard-dose (initial and incremental rates of 2 milliunits/min) oxytocin regimens. The primary outcome was cesarean birth. Prespecified secondary outcomes included labor duration, clinical chorioamnionitis, endometritis, postpartum hemorrhage, Apgar score 3 or less at 5 minutes, umbilical artery acidemia, neonatal intensive care unit admission, perinatal death, and a severe perinatal morbidity composite. A sample size of 501 per group (n=1,002) was planned to detect a 6.6% absolute reduction in rate of the primary outcome, from 20% in the standard-dose group to 13.4% in the high-dose group with 80% power.RESULTS:From September 2015 to September 2020, 1,003 participants were randomized - 502 assigned to high-dose and 501 assigned to standard dosing. The majority of participants were of White race, were married or living as married, and had commercial insurance. Baseline characteristics between groups were similar. The primary outcome occurred in 14.5% of those receiving high-dose compared with 14.4% of those receiving standard-dose oxytocin (relative risk, 1.01; 95% CI 0.75-1.37). The high-dose group had a significantly shorter mean labor duration (9.1 vs 10.5 hours; P<.001), and a significantly lower chorioamnionitis incidence (10.4% vs 15.6%; relative risk, 0.67; 95% CI 0.48-0.92) compared with standard dosing. Umbilical artery acidemia was significantly less frequent in the high-dose group in complete case analysis, but this finding did not persist after multiple imputation (relative risk, 0.55; 95% CI 0.29-1.04). There were no significant differences in other secondary outcomes.CONCLUSION:Among nulliparous participants who were undergoing augmentation of labor, a high-dose oxytocin regimen, compared with standard dosing, did not affect the cesarean birth risk but significantly reduced labor duration and clinical chorioamnionitis frequency without adverse effects on perinatal outcomes.CLINICAL TRIAL REGISTRATION:ClinicalTrials.gov, NCT02487797.
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U2 - 10.1097/AOG.0000000000004399
DO - 10.1097/AOG.0000000000004399
M3 - Article
C2 - 33957657
AN - SCOPUS:85107085392
SN - 0029-7844
VL - 137
SP - 991
EP - 998
JO - Obstetrics and gynecology
JF - Obstetrics and gynecology
IS - 6
ER -
