Outcomes with cesarean section versus vaginal birth in extremely preterm breech singletons

Yanchen Wang; Pasqualina Santaguida; Sameer Parpia; Fabiana Bacchini; Prakesh S Shah; Kellie E Murphy; Sandesh Shivananda; Sarah D McDonald; Canadian Neonatal Network and Canadian Preterm Birth Network Investigators

doi:10.1016/j.ajog.2025.07.016

Outcomes with cesarean section versus vaginal birth in extremely preterm breech singletons

Am J Obstet Gynecol. 2025 Jul 11:S0002-9378(25)00476-4. doi: 10.1016/j.ajog.2025.07.016. Online ahead of print.

Authors

Yanchen Wang¹, Pasqualina Santaguida², Sameer Parpia³, Fabiana Bacchini⁴, Prakesh S Shah⁵, Kellie E Murphy⁶, Sandesh Shivananda⁷, Sarah D McDonald⁸; Canadian Neonatal Network and Canadian Preterm Birth Network Investigators

Collaborators

Canadian Neonatal Network and Canadian Preterm Birth Network Investigators:
Marc Beltempo, Prakesh S Shah, Thevanisha Pillay, Jonathan Wong, Miroslav Stavel, Rebecca Sherlock, Ayman Abou Mehrem, Jennifer Toye, Joseph Ting, Carlos Fajardo, Andrei Harabor, Lannae Strueby, Mary Seshia, Deepak Louis, Chelsea Ruth, Ann Yi, Amit Mukerji, Orlando Da Silva, Sajit Augustine, Kyong-Soon Lee, Eugene Ng, Brigitte Lemyre, Brigitte Lemyre, Faiza Khurshid, Victoria Bizgu, Nina Nouraeyan, Keith Barrington, Anie Lapointe, Guillaume Ethier, Christine Drolet, Martine Claveau, Marie St-Hilaire, Valerie Bertelle, Edith Masse, Paloma Costa, Hala Makary, Ahmad Aziz, Gabriela de Carvalho Nunes, Wissam Alburaki, Jo-Anna Hudson, Jehier Afifi, Andrzej Kajetanowicz, Bruno Piedboeuf, Wendy Whittle, Swati Agarwal, Kenneth Lim, Jessica Liauw, Darine El-Chaar, Katherine Theriault, Marie-Ève Roy-Lacroix, Kimberly Butt, Candace O'Quinn, Christy Pylypjuk, Isabelle Boucoiran, Catherine Taillefer, Joan Crane, Haim Abenhaim, Graeme Smith, Karen Wou, Sue Chandra, Jagdeep Ubhi, Ernesto Figueiro-Filho, Michael Helewa, Ariadna Grigoriu, Rob Gratton, Cynthia Chan, Gabriela de Caralho Nunes, Ludmila Porto, Nir Melamed, Jason Burrows, Sajit Augustine, Lara Wesson, Erin MacLellan, James Hayward, Victoria Allen

Affiliations

¹ Department of Obstetrics and Gynecology, McMaster University, 1280 Main St. West, Hamilton, ON, L8S 4K1, Canada; Department of Health Research Methods, Evidence, and Impact, McMaster University, 1280 Main St. West, Hamilton, ON, L8S 4K1, Canada.
² Department of Health Research Methods, Evidence, and Impact, McMaster University, 1280 Main St. West, Hamilton, ON, L8S 4K1, Canada.
³ Department of Health Research Methods, Evidence, and Impact, McMaster University, 1280 Main St. West, Hamilton, ON, L8S 4K1, Canada; Department of Oncology, McMaster University, 1280 Main St. West, Hamilton, Ontario, L8S 4K1, Canada.
⁴ Canadian Premature Babies Foundation, 4225B Dundas St. West, Etobicoke, Ontario, M8X 1Y3, Canada.
⁵ Department of Pediatrics, Mount Sinai Hospital and University of Toronto, 600 University Ave, Toronto, ON, M5G 1X5, Canada.
⁶ Division of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, Mount Sinai Hospital, University of Toronto, 600 University Ave, Toronto, Ontario, M5G 1X5, Canada.
⁷ Division of Neonatology, Department of Pediatrics, University of British Columbia and B.C. Women's Hospital & Health Centre, 4500 Oak St, Vancouver, British Columbia, V6H 3N1, Canada.
⁸ Department of Obstetrics and Gynecology, McMaster University, 1280 Main St. West, Hamilton, ON, L8S 4K1, Canada; Department of Health Research Methods, Evidence, and Impact, McMaster University, 1280 Main St. West, Hamilton, ON, L8S 4K1, Canada; Division of Maternal-Fetal Medicine, McMaster University, 1280 Main St. West, Hamilton, ON, L8S 4K1, Canada; Department of Radiology, McMaster University, 1280 Main St. West, Hamilton, ON, L8S 4K1, Canada. Electronic address: mcdonals@mcmaster.ca.

PMID: 40653067
DOI: 10.1016/j.ajog.2025.07.016

Abstract

Background: Decision-making regarding breech extremely preterm mode of birth is difficult. Seeming benefits with cesarean section in previous studies may have been due to other factors that had not been adequately accounted for.

Objective: To determine the association of cesarean section versus vaginal birth with neonatal outcomes among liveborn extremely preterm breech singletons who received active care at birth.

Study design: This population-based cohort study included all liveborn breech singletons between 23 and 27 weeks' gestation from 2010 to 2022, who received active resuscitation including those who died in the resuscitation room. We excluded outborn infants and those with major congenital anomalies. Our primary outcome was a composite of death, severe neurological complications, or birth trauma (mainly intracranial or other hemorrhage). The primary analysis comparing infants born by cesarean section versus vaginally used a generalized estimating equation Poisson regression model; sensitivity analyses included propensity score matching.

Results: From the 3332 extremely preterm breech singletons, 83.4% (2778/3332) were born by cesarean section. The adjusted incidence of mortality/severe morbidity was lower in the cesarean section group than in the vaginal birth group (26.1% versus 33.7%, respectively, adjusted relative risk of 0.77, 95% confidence interval: 0.63, 0.95, with adjustment for 14 factors including gestational age at birth). The reduction in mortality/severe morbidity following cesarean section persisted: after propensity score matching (adjusted relative risk: 0.69, 95% confidence interval: 0.53, 0.89), and in those receiving optimized perinatal care (all of: antenatal corticosteroids, antenatal magnesium sulfate, and deferred cord clamping) or likely in those without optimized perinatal care, and in the subgroups of singletons born early (23-24 weeks) or likely later (25-27 weeks).

Conclusions: Extremely preterm breech singleton birth by cesarean section was associated a reduction in mortality/severe morbidity. This association was robust and consistently observed in analyses addressing potential confounding through different methods, and in clinical-relevant scenarios. Given that all three previous randomized controlled trials were stopped early due to recruitment challenges, this type of cohort data are the best available evidence for decision-making.

Keywords: Breech presentation; Cesarean section; Extremely preterm singletons; Neonatal outcomes; Optimized perinatal care.