Publication of the results of the Randomized Trial of Induction Versus Expectant Management (ARRIVE) study in August 2018 has been one of the most discussed obstetric papers in recent years. ARRIVE was a randomised controlled trial of induction versus expectant management of pregnancies in low-risk nulliparous women at term.¹ This large multi-centre American trial was conducted from March 2014 to August 2017. The trial approached 22,533 eligible women at between 38 and 39 weeks gestation in their first pregnancy, of which 6106 (27 per cent) provided informed consent and underwent randomisation to either be induced at 39 weeks (between 39+0 and 39+4 days), or await labour until at least 40+5 days’ gestation and no longer than 42+2 days. The primary composite neonatal outcome comprising perinatal death (respiratory support within 72 hours of birth, Apgar score of three or less at five minutes, hypoxic-ischemic encephalopathy, seizure, infection, meconium aspiration syndrome, birth trauma, intracranial or subgaleal haemorrhage, or neonatal hypotension requiring vasopressor support) did not differ significantly between the induction (4.3%) and expectant management group (5.4%; RR=0.80; 95% CI 0.64 to 1.00). There was a significantly lower caesarean section rate in the induction group compared to the expectant management group (18.6% vs 22.2%; RR=0.84; 95% CI 0.76 to 0.93), as well as a lower rate of hypertensive disorders in pregnancy in the induction group (9.1% vs 14.1%; RR=0.64; 95% CI 0.56 to 0.74). Women in the induction group spent longer in the delivery suite compared to woman in the expectant management group, and reported a higher median score on the Labour Agentry Scale, indicating a perceived higher degree of control during labour.¹

The authors’ concluding paragraph was: ‘In summary, we found that elective labour induction at 39 weeks of gestation did not result in a greater frequency of perinatal adverse outcomes than expectant management and resulted in fewer instances of caesarean delivery. These results suggest that policies aimed at the avoidance of elective labour induction among low-risk nulliparous women at 39 weeks of gestation are unlikely to reduce the rate of caesarean delivery on a population level; the trial provides information that can be incorporated into discussions that rely on principles of shared decision-making.’¹

Publication of this study has stimulated considerable debate within the obstetric community, with a relatively measured and practical approach being advocated by the American College of Obstetricians and Gynecologists in a recent practice advisory guideline: ‘Based on the findings demonstrated in this trial, it is reasonable for obstetricians and healthcare facilities to offer elective induction of labour to low-risk nulliparous women at 39 weeks gestation. However, consideration for enactment of this elective induction of labour intervention should not only take into account the trial findings, but that this recommendation may be conditional upon the values and preferences of the pregnant woman, the resources available (including personnel), and the setting in which the intervention will be implemented. A collaborative discussion with shared decision-making should take place with the pregnant woman.’²

1. Grobman WA, Rice MM, Reddy UM, et al. Labor induction versus expectant management in low-risk nulliparous women. N Engl J Med. 2018 Aug 9;379(6):513-523.
2. American College of Obstetricians and Gynecologists. Practice Advisory: Clinical guidance for integration of the findings of the ARRIVE Trial: Labor induction versus expectant management in low-risk nulliparous women. Available from: www.acog.org/Clinical-Guidance-and-Publications/Practice-Advisories/Practice-Advisory-Clinical-guidance-for-integration-of-the-findings-of-The-ARRIVE-Trial retrieved 1 October 2018.