(1152) Mode of Delivery and Neonatal Survival Among Periviable Vertex Singleton Pregnancies

Friday, January 31, 2025

4:00 PM – 6:00 PM

Submitting Author and Presenting Author(s)

Peeraya S. Sawangkum, MD (she/her/hers)

Maternal Fetal Medicine Fellow
Department of Obstetrics and Gynecology, University of South Florida
Tampa, Florida, United States

Coauthor(s)

JS

Jason L. Salemi, MPH, PhD

Professor
Department of Obstetrics and Gynecology, University of South Florida
Tampa, Florida, United States
JT

Jean Paul P. Tanner, MPH, PhD

Assistant Professor
Department of Obstetrics and Gynecology, University of South Florida
Tampa, Florida, United States
AE

Alexia Eiges, MD

Department of Obstetrics and Gynecology, University of South Florida
Nashville, Tennessee, United States
Anjali J. Kaimal, MD (she/her/hers)

Professor and Vice Chair of Clinical Operations, Department of OBGYN
University of South Florida
Tampa, Florida, United States

Objective: To determine the association between mode of delivery and neonatal survival for periviable, vertex, singleton gestations.

Study Design: Retrospective cohort study using a maternal-infant linked database of live births in Florida from 2006 to 2019. Vertex, singleton deliveries of infants born at 22w0d to 25w6d with attempted neonatal resuscitation were included. We calculated risk ratios (RRs) for binary outcomes and hazard ratios (HRs) for time-to-event outcomes that were adjusted for confounders. Outcomes were examined overall and stratified by week of gestation. A planned sensitivity analysis was performed examining outcomes in neonates who survived beyond 24 hours of life.

Results: A total of 4,820 periviable deliveries were identified. Of those, 2,472 (51.3%) were cesarean deliveries. People who underwent cesarean delivery were more likely to have hypertension and diabetes. In the overall model, vaginal delivery was associated with a higher risk of mortality at 24 hours (aRR 1.20, 95% CI 1.01-1.44), lower risk of mortality at 7 days (aRR 0.88, 95% CI 0.79-0.99), but no difference in mortality at 28 days (aRR 0.94, 95% CI 0.86-1.02) or 1 year (aRR 0.95, 95% CI 0.89-1.03). After excluding neonates who died within the first 24 hours, vaginal delivery was associated with lower risk of mortality, with aRR of 0.70 (95% CI 0.59-0.83) at 7 days, aRR of 0.87 (95% CI 0.77-0.97) at 28 days, and aRR of 0.91 (95% CI 0.83-1.00) at 1 year. Stratified analyses by gestational age demonstrated increased mortality with vaginal delivery among 22w- and 23w-neonates (aHR 1.48, 95% CI 1.06-2.06 and aHR 1.19, 95% CI 1.01-1.43 respectively), but decreased mortality with vaginal delivery among 24w- and 25w-neonates (aHR 0.75, 95% CI 0.63-0.89 and aHR of 0.72, 95% CI 0.58-0.90 respectively).

Conclusion: Our study demonstrates the effect of mode of delivery on neonatal survival in the periviable period is dependent upon gestational age. Further study is needed to understand the clinical situations in which cesarean is most likely to improve neonatal outcome in order to balance this against potential maternal complications.