Abstract
Objective We aim to examine the population-level rates of induction, stillbirth, perinatal
mortality, and neonatal death before and after the ARRIVE (A Randomized Trial of Induction
Versus Expectant Management) trial.
Study Design This study was a cross-sectional analysis of publicly available U.S. Live Birth data
linked with Infant Death and Fetal Death certificate data from National Vital Statistics
Online. We limited analyses to nulliparous individuals with singleton pregnancy and
cephalic presentation who delivered at 39 weeks or greater. The pre- and post-ARRIVE
periods spanned from August 2016 to July 2018, and from January 2019 to December 2020,
respectively. Our primary outcome was a stillbirth. Secondary outcomes included induction
of labor, perinatal mortality, and neonatal death. Outcomes were compared between
the pre- and post-ARRIVE periods. Modified Poisson regression was used to calculate
adjusted relative risks (aRRs).
Results Of 2,817,071 births, there were 1,454,346 births in the pre-ARRIVE period and 1,362,725
in the post-ARRIVE period; there were 1,196 and 1,062 stillbirths in the pre- and
post-ARRIVE periods, respectively. Compared to the pre-ARRIVE period, the post-ARRIVE
period was not associated with a significant decrease in the risk of stillbirth at
39 weeks or greater (aRR = 0.92 [95% confidence interval (95% CI): 0.85–1.00]) and
stillbirth at 40 weeks or greater (aRR = 0.92 [95% CI: 0.82–1.04]). Compared to the
pre-ARRIVE trial period, the post-ARRIVE trial was associated with increased rates
of induction of labor at 39 weeks (aRR = 1.37 [95% CI: 1.37–1.38]) and 40 weeks (aRR = 1.24
[95% CI: 1.24–1.25]. Similar to stillbirth, there was no significant decrease in the
risk of perinatal mortality at 39 weeks or greater or 40 weeks or greater. There was
also no statistically significant change in neonatal death rates at 39 weeks or greater
or at 40 weeks or greater.
Conclusion The increase in induction of labor at 39 weeks was not large enough to impact the
stillbirth rate at 39 weeks or greater.
Key Points
-
Post-ARRIVE trial, rate of induction of labor increased at 39 and 40 weeks.
-
Post-ARRIVE trial, stillbirth and perinatal mortality rates remained unchanged.
-
Induction rate rise post-ARRIVE trial did not impact neonatal death rates.
Keywords
induction of labor - neonatal death - perinatal mortality
