The price of waiting: hospital utilization among elective inductions of labor at increasing gestational age

To assess how hospital utilization rates change when elective induction is delayed beyond 39 weeks gestation in a real-world maternity setting. Retrospective cohort study of all women undergoing elective inductions (eIOL) by both physicians and midwives at a large Midwestern tertiary care center from January 1st 2019 to January 1st, 2021. Inclusion criteria were all singleton, vertex, non-anomalous gestations undergoing eIOL at 39w0d and beyond. Exclusion criteria were any inductions for medical indications and multiple gestations. The primary exposure was the week of gestational age at which the eIOL occurred, stratified into discrete gestational age intervals: 39w0d - 39w6d; 40w0d - 40w6d; 41w0d and beyond. The primary outcomes were time between labor admission and delivery; time between delivery and discharge; total length of maternal hospital stay; and maternal hospital stays that that were 3 days or greater. Test for trend was applied across GA weeks for the composite and component outcomes. Of 1847 patients who met inclusion, 44% were nulliparous; 9% were midwife-managed, 10% were family medicine-managed, and 81% were OB-managed patients. There was a statistically significant increase in all primary outcomes with advancing gestational age. Specifically median labor admit to delivery time increased from 19-20 hours, to 25 hours across the GA strata (p < 0.0001) and total maternal hospital stay of 3+ days increased from 20% in the 39th week to 32% at 41+ weeks (p=0.0001) (TABLE). In a heterogenous obstetric population with diverse delivering providers in a real-world setting, there is evidence that eIOL in the 39th week is associated with a lower rate of hospital utilization. This data serves as guidance that 39 week IOL among nulliparous and multiparous women does not come at the expense of increasing labor & delivery utilization and is in fact associated with lower labor & delivery utilization.