Elective Induction Rates and Outcomes in Low-Risk Nulliparous and Multiparous Patients Following the ARRIVE Trial: A Regional Cohort Study from South Central Louisiana
Location
Center for Advanced Learning & Simulation (CALS)
Publication Date
May 2026
Start Date
8-5-2026 11:30 AM
End Date
8-5-2026 11:45 AM
Description
Background: The ARRIVE trial was a landmark study published in 2018 that investigated elective inductions of labor between 39 0/7 – 39 4/7 weeks gestational age compared to expectant management. This study found that elective inductions at 39 weeks were associated with a decreased cesarean delivery rate and no adverse neonatal outcomes. However, data on real-world adoption and outcomes following the publication of ARRIVE, particularly in more diverse regions compared to the trial setting, remain limited. This study aims to determine the changes in elective induction rates and outcomes at our institution after the ARRIVE trial publication.
Methods: A retrospective cohort study utilizing Woman’s Hospital’s Women and Infants Clinical (WINC) database was performed spanning 2016 to 2021. Our analysis included data divided into pre-and post-ARRIVE. Pre-ARRIVE data spanned January 1, 2016, through July 31, 2018, prior to publication of the ARRIVE trial. We excluded August 2018 to allow for adoption of practice changes based on the ARRIVE results. Post-ARRIVE data included September 1st, 2018, to March 31st, 2021. Each period had an equal number of calendar days (n = 943) to facilitate comparison. Inclusion and exclusion criteria were similar to the ARRIVE trial. We identified low-risk nulliparous, term, vertex and singleton pregnancies that had an elective induction between 39 0/7 and 39 4/7 weeks gestational age. We also identified low-risk multiparous individuals with similar gestational age range, no prior cesarean, vertex, and singleton. Individuals with contraindications to vaginal delivery, PROM, multiple gestation, fetal growth restriction, fetal anomaly, or any medical indication for induction were excluded.
Results: Our study included a total of 6518 low risk nulliparous and multiparous patients divided into pre-ARRIVE (N=3273) and post-ARRIVE (N=3245). Odds of elective induction increased significantly in the post-ARRIVE period (OR 1.26, 95% CI 1.14–1.39, p<0.001). We did not see a significant decrease in the odds of a cesarean delivery when comparing pre-and post-ARRIVE groups (OR 1.00, 95% CI 0.86-1.15, p=0.96). Other variables, including the odds of gestational hypertension diagnosis, pre-eclampsia diagnosis, and NICU admissions were not significantly different between pre-and post-ARRIVE groups. The odds of hemorrhage were approximately twice as high in the post-ARRIVE group compared to the pre-ARRIVE group (OR 2.1, 95% CI 1.62-2.73, p<0.001).
Conclusions: We observed a statistically significant increase in the odds of elective inductions after publication of the ARRIVE trial, suggesting a shift in clinical practice. However, unlike the ARRIVE trial, we did not find a significant reduction in the odds of cesarean delivery or hypertensive disorders of pregnancy. Differences in study design, patient population, and the transitional nature of the post-ARRIVE period may account for the differences in findings between our study and the original trial. Interestingly, the odds of hemorrhage were significantly higher in the post-ARRIVE group. This may be due to practice changes in blood loss documentation in deliveries (estimated to quantitative) that were adopted during the study period. Future work will examine a longer post-ARRIVE period to determine whether elective induction rates and associated outcomes continue to evolve as practice patterns mature.
Recommended Citation
Oliver, Katherine MD; Florence, Elizabeth MD; Sutton, Elizabeth F. PhD; Dinh, Dina MS; and Collins, J. Hunter PhD, "Elective Induction Rates and Outcomes in Low-Risk Nulliparous and Multiparous Patients Following the ARRIVE Trial: A Regional Cohort Study from South Central Louisiana" (2026). Dept. of Obstetrics & Gynecology Resident Research Day. 10.
https://digitalscholar.lsuhsc.edu/obgyn_rd/2026/presentations/10
Elective Induction Rates and Outcomes in Low-Risk Nulliparous and Multiparous Patients Following the ARRIVE Trial: A Regional Cohort Study from South Central Louisiana
Center for Advanced Learning & Simulation (CALS)
Background: The ARRIVE trial was a landmark study published in 2018 that investigated elective inductions of labor between 39 0/7 – 39 4/7 weeks gestational age compared to expectant management. This study found that elective inductions at 39 weeks were associated with a decreased cesarean delivery rate and no adverse neonatal outcomes. However, data on real-world adoption and outcomes following the publication of ARRIVE, particularly in more diverse regions compared to the trial setting, remain limited. This study aims to determine the changes in elective induction rates and outcomes at our institution after the ARRIVE trial publication.
Methods: A retrospective cohort study utilizing Woman’s Hospital’s Women and Infants Clinical (WINC) database was performed spanning 2016 to 2021. Our analysis included data divided into pre-and post-ARRIVE. Pre-ARRIVE data spanned January 1, 2016, through July 31, 2018, prior to publication of the ARRIVE trial. We excluded August 2018 to allow for adoption of practice changes based on the ARRIVE results. Post-ARRIVE data included September 1st, 2018, to March 31st, 2021. Each period had an equal number of calendar days (n = 943) to facilitate comparison. Inclusion and exclusion criteria were similar to the ARRIVE trial. We identified low-risk nulliparous, term, vertex and singleton pregnancies that had an elective induction between 39 0/7 and 39 4/7 weeks gestational age. We also identified low-risk multiparous individuals with similar gestational age range, no prior cesarean, vertex, and singleton. Individuals with contraindications to vaginal delivery, PROM, multiple gestation, fetal growth restriction, fetal anomaly, or any medical indication for induction were excluded.
Results: Our study included a total of 6518 low risk nulliparous and multiparous patients divided into pre-ARRIVE (N=3273) and post-ARRIVE (N=3245). Odds of elective induction increased significantly in the post-ARRIVE period (OR 1.26, 95% CI 1.14–1.39, p<0.001). We did not see a significant decrease in the odds of a cesarean delivery when comparing pre-and post-ARRIVE groups (OR 1.00, 95% CI 0.86-1.15, p=0.96). Other variables, including the odds of gestational hypertension diagnosis, pre-eclampsia diagnosis, and NICU admissions were not significantly different between pre-and post-ARRIVE groups. The odds of hemorrhage were approximately twice as high in the post-ARRIVE group compared to the pre-ARRIVE group (OR 2.1, 95% CI 1.62-2.73, p<0.001).
Conclusions: We observed a statistically significant increase in the odds of elective inductions after publication of the ARRIVE trial, suggesting a shift in clinical practice. However, unlike the ARRIVE trial, we did not find a significant reduction in the odds of cesarean delivery or hypertensive disorders of pregnancy. Differences in study design, patient population, and the transitional nature of the post-ARRIVE period may account for the differences in findings between our study and the original trial. Interestingly, the odds of hemorrhage were significantly higher in the post-ARRIVE group. This may be due to practice changes in blood loss documentation in deliveries (estimated to quantitative) that were adopted during the study period. Future work will examine a longer post-ARRIVE period to determine whether elective induction rates and associated outcomes continue to evolve as practice patterns mature.
Comments
Advisor: Elizabeth Florence MD