Changes in obstetrical practices and pregnancy outcomes following the ARRIVE trial

Published:February 05, 2022DOI:


      The ARRIVE trial demonstrated the benefit of induction of labor at 39 weeks gestation. Obstetrics departments across the United States faced the challenge of adapting clinical practice in light of these data while managing logistical constraints.


      To determine if there were changes in obstetrical practices and perinatal outcomes in the United States after the ARRIVE trial publication.

      Study Design

      This was a population-based retrospective cohort study of low-risk, nulliparous women who initiated prenatal care by 12 weeks gestation with singleton, nonanomalous pregnancies delivering at ≥39 weeks. Data were obtained from the US Natality database. The pre-ARRIVE group were women who delivered between January 1, 2015 and December 31, 2017. The post-ARRIVE group consisted of women who delivered between January 1, 2019 and December 31, 2019. Births that occurred in 2018 were excluded. Practice outcomes were rates of induction of labor, timing of delivery, and cesarean delivery rate. Adverse maternal outcomes were blood transfusion and admission to medical intensive care unit. Adverse neonatal outcomes were need for assisted ventilation (immediate and >6 hours), 5-minute APGAR score <3, neonatal intensive care unit admission, seizures, and surfactant use. Univariate and multivariate analyses were performed. Trends were tested across the time period represented by the pre-ARRIVE group using Cochran–Armitage trend test.


      There were 1,966,870 births in the pre-ARRIVE group and 609,322 in the post-ARRIVE group. The groups differed in age, race, body mass index, marital status, infertility treatment, and smoking history (P<.001). After adjusting for these differences, the post-ARRIVE group was more likely to undergo induction (36.1% vs 30.2%; adjusted odds ratio, 1.36 [1.36–1.37]) and deliver by 39+6 weeks of pregnancy (42.8% vs 39.9%; adjusted odds ratio, 1.14 [1.14–1.15]). The post-ARRIVE group had a significantly lower rate of cesarean delivery than the pre-ARRIVE group (27.3 % vs 27.9%; adjusted odds ratio, 0.94 [0.93–0.94]). Patients in the post-ARRIVE group were more likely to receive a blood transfusion (0.4% vs 0.3%; adjusted odds ratio, 1.43 [1.36–1.50]) and be admitted to medical intensive care unit (0.09% vs 0.08%; adjusted odds ratio, 1.20 [1.09–1.33]). Neonates in the post-ARRIVE group were more likely to need assisted ventilation at birth (3.5% vs 2.8%; adjusted odds ratio, 1.28 [1.26–1.30]) and >6 hours (0.6% vs 0.5%; adjusted odds ratio, 1.36 [1.31–1.41]). The neonates in the post-ARRIVE group were more likely to have low 5-minute APGAR scores (0.4% vs 0.3%; adjusted odds ratio, 0.91 [0.86–0.95]). Neonatal intensive care unit admission did not differ between the 2 groups (4.9% vs 4.9%; adjusted odds ratio, 1.01 [0.99–1.03]). There were no differences in neonatal seizures (0.04% vs 0.04%; adjusted odds ratio, 0.97 [0.84–1.13]), and surfactant use (0.08% vs 0.07%; adjusted odds ratio, 1.05 [0.94–1.17]) between the 2 groups.


      There were more inductions of labor, more deliveries at 39 weeks’ gestation, and fewer cesarean deliveries in the year after the ARRIVE trial publication. The small but statistically significant increase in some adverse maternal and neonatal outcomes should be explored to determine if they are related with concurrent changes in obstetrical practices.

      Key words

      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to American Journal of Obstetrics & Gynecology
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • World Health Organization
        Caesarean section rates continue to rise, amid growing inequalities in access.
        (Available at:)
        • Keag O.E.
        • Norman J.E.
        • Stock S.J.
        Long-term risks and benefits associated with cesarean delivery for mother, baby, and subsequent pregnancies: systematic review and meta-analysis.
        PLoS Med. 2018; 15e1002494
        • The American College of Obstetricians and Gynecologists
        Safe prevention of the primary cesarean delivery.
        (Available at:)
        • Attanasio L.B.
        • Paterno M.T.
        Correlates of trial of labor and vaginal birth after cesarean in the United States.
        J Womens Health (Larchmt). 2019; 28: 1302-1312
        • Hersh A.R.
        • Skeith A.E.
        • Sargent J.A.
        • Caughey A.B.
        Induction of labor at 39 weeks of gestation versus expectant management for low-risk nulliparous women: a cost-effectiveness analysis.
        Am J Obstet Gynecol. 2019; 220: 590.e1-590.e10
        • Kim H.I.
        • Choo S.P.
        • Han S.W.
        • Kim E.H.
        Benefits and risks of induction of labor at 39 or more weeks in uncomplicated nulliparous women: a retrospective, observational study.
        Obstet Gynecol Sci. 2019; 62: 19-26
        • Sinkey R.G.
        • Lacevic J.
        • Reljic T.
        • et al.
        Elective induction of labor at 39 weeks among nulliparous women: the impact on maternal and neonatal risk.
        PLoS One. 2018; 13e0193169
        • Tita A.T.N.
        • Lai Y.
        • Bloom S.L.
        • et al.
        Timing of delivery and pregnancy outcomes among laboring nulliparous women.
        Am J Obstet Gynecol. 2012; 206: 239.e1-239.e8
        • Page J.M.
        • Snowden J.M.
        • Cheng Y.W.
        • Doss A.E.
        • Rosenstein M.G.
        • Caughey A.B.
        The risk of stillbirth and infant death by each additional week of expectant management stratified by maternal age.
        Am J Obstet Gynecol. 2013; 209: 375.e1-375.e7
        • Grobman W.A.
        • Rice M.M.
        • Reddy U.M.
        • et al.
        Labor induction versus expectant management in low-risk nulliparous women.
        N Engl J Med. 2018; 379: 513-523
        • Grobman W.A.
        • Caughey A.B.
        Elective induction of labor at 39 weeks compared with expectant management: a meta-analysis of cohort studies.
        Am J Obstet Gynecol. 2019; 221: 304-310
        • American College of Obstetricians and Gynecologists
        ACOG response to ARRIVE trial.
        (Available at:)
        • Facchinetti F.
        • Menichini D.
        • Perrone E.
        The ARRIVE trial will not “arrive” to Europe.
        J Matern Fetal Neonatal Med. 2020; ([Epub ahead of print])
        • Migliorelli F.
        • De Oliveira S.S.
        • Martínez de Tejada B.
        The ARRIVE Trial: towards a universal recommendation of induction of labour at 39 weeks?.
        Eur J Obstet Gynecol Reprod Biol. 2020; 244: 192-195
        • Bero L.A.
        • Grilli R.
        • Grimshaw J.M.
        • Harvey E.
        • Oxman A.D.
        • Thomson M.A.
        Closing the gap between research and practice: an overview of systematic reviews of interventions to promote the implementation of research findings. The Cochrane Effective Practice and Organization of Care Review Group.
        BMJ. 1998; 317: 465-468
        • Centers for Disease Control and Prevention
        Stats of the states—cesarean delivery rates.
        (Available at:)
        • Vardo J.H.
        • Thornburg L.L.
        • Glantz J.C.
        Maternal and neonatal morbidity among nulliparous women undergoing elective induction of labor.
        J Reprod Med. 2011; 56: 25-30
        • Dunne C.
        • Da Silva O.
        • Schmidt G.
        • Natale R.
        Outcomes of elective labour induction and elective caesarean section in low-risk pregnancies between 37 and 41 weeks’ gestation.
        J Obstet Gynaecol Can. 2009; 31: 1124-1130
      1. ACOG Practice Bulletin No. 107: induction of labor.
        Obstet Gynecol. 2009; 114: 386-397
        • Osmundson S.
        • Ou-Yang R.J.
        • Grobman W.A.
        Elective induction compared with expectant management in nulliparous women with an unfavorable cervix.
        Obstet Gynecol. 2011; 117: 583-587
        • Stock S.J.
        • Ferguson E.
        • Duffy A.
        • Ford I.
        • Chalmers J.
        • Norman J.E.
        Outcomes of elective induction of labour compared with expectant management: population based study.
        BMJ. 2012; 344: e2838
        • Dube S.R.
        • Asman K.
        • Malarcher A.
        • Carabollo R.
        Cigarette smoking among adults and trends in smoking cessation - United States, 2008.
        Morb Mortal Wkly Rep. 2009; 58: 1227-1232
        • Kozhimannil K.B.
        • Shippee T.P.
        • Adegoke O.
        • Vemig B.A.
        Trends in hospital-based childbirth care: the role of health insurance.
        Am J Manag Care. 2013; 19: e125-e132