(961) Risk of severe maternal morbidity and mortality in relation to ARRIVE trial

Friday, January 31, 2025

4:00 PM – 6:00 PM

Submitting Author and Presenting Author(s)

Amanda M. Baucom, MBA, MD (she/her/hers)

MFM Fellow
University of Cincinnati
Cincinnati, Ohio, United States

Coauthor(s)

Heather N. Czarny, MD (she/her/hers)

Fellow
University of Cincinnati College of Medicine
Cincinnati, Ohio, United States
Robert M. Rossi, MD

Assistant Professor
University of Cincinnati College of Medicine
Cincinnati, Ohio, United States
Isabella Toledo, MD (she/her/hers)

Resident
Indiana University School of Medicine
Indianapolis, IN, United States

Objective: Since the 2018 ARRIVE (A Randomized Trial of Induction versus Expectant Management) trial, the rate of elective 39-week induction has increased. However, the population impact of this trial on obstetric and maternal outcomes is unknown. This study aims to evaluate trends in severe maternal morbidity (SMM) and obstetrical outcomes among low-risk term patients following the ARRIVE trial.

Study Design: This study is a population-based, retrospective cohort analysis of U.S. delivery hospitalizations, utilizing data from the National Inpatient Sample database. Deliveries were identified using ICD-10 codes and categorized into two epochs: Epoch 1, Pre-ARRIVE (2015 Q4 to 2018 Q2), and Epoch 2, Post-ARRIVE (2019 Q2 to 2021 Q4), with the dissemination phase 2018 Q3 to 2019 Q1. Patients with medical indications for induction, outlined by the ARRIVE trial, were excluded. SMM was defined according to the CDC with related subgroups. The primary outcome was the difference in risks (aRR, 95% CI) of SMM and obstetrical outcomes as estimated by multivariate logistic regression analyses.

Results: Among 8,404,920 deliveries, the rate of 39-week delivery increased from 52.4% to 57.7% (P< 0.001) among low-risk patients. The rate of SMM increased (0.31 vs 0.38%, p< 0.001), while cesarean delivery decreased (14.0 vs 13.8%, p=0.0422) between Epoch 1 and 2. Risk of SMM increased (aRR 1.20, CI 1.12-1.28), as did SMM subgroups including acute renal failure, respiratory SMM, sepsis, shock, and hemorrhagic SMM (Fig. 1). Eclampsia rates decreased (aRR 0.59, CI 0.49-0.72), despite an increase in pregnancy-associated hypertension. There were also reductions in cesarean delivery (aRR 0.97, CI 0.95-0.98), obstetric anal sphincter injury (aRR 0.96, CI 0.94-0.98), and hospital length of stay exceeding the 95th% (aRR 0.91, CI 0.87-0.95) (Fig 2).

Conclusion: Following the ARRIVE trial, there has been an increase in SMM and pregnancy-related hypertension. However, there has been a decrease in the rates of eclampsia, OASIS, and cesarean sections, suggesting a complex potential impact of the ARRIVE trial on outcomes in low-risk patients.