Methods and Modes of delivery

Lead Investigators

Dr. Mark Walker

Dr. Shi Wu Wen

Dr. Darine El-Chaâr

Dr. Mary Guo

Dr. Laura Gaudet

Caesarean sections are the most common inpatient surgical procedures in North America. Caesarean sections may be medically indicated for reasons including complications during pregnancy or the labour process, and issues compromising fetal growth and wellbeing. Pregnant individuals living with obesity and those with diabetes during pregnancy are also more likely to be submitted for caesarean section. Further, some pregnant individuals without medical indications may request Caesearan deliveries for reasons including scheduling convenience, anxiety about labour pain and process, and fear surrounding possible pelvic floor damage and sexual dysfunction after vaginal delivery.  

Thus, whereas unique populations and scenarios may require caesarean sections for the health and wellbeing of the birthing parent and the fetus/neonate, others receive the procedure in the absence of medical indications. This research program explores the optimal timing, mode and method of delivery across obstetrical sub-populations, and examines the risk factors and short and long-term maternal and offspring outcomes associated with caesarean sections compared to vaginal deliveries. 


  • An epidemiologic research program to improve maternal and child health. Canadian Institutes of Health Research. Foundation Grant. Principal Applicants: Walker MC, Wen SW. ($9,876,973)(2016-2022; extended to 2026) 
  • OaK 2016-2021: Investigating Contemporary Topics in OB/MFM. Canadian Institutes of Health Research. Team Grant: Clinician-Investigator Teams in Obstetrics & Maternal-Fetal Medicine. Principal Applicants: Gaudet LM, Velez MDP. ($736,960) (2016-2020) 
Select Publications:
  • Wen SW, Murphy, MSQ, Walker M, El-Chaar D. Does cesarean delivery on maternal request cause adverse outcomes?. American Journal of Obstetrics and Gynecology. 2022. S0002-9378(22)00351-9. doi: 10.1016/j.ajog.2022.05.007.  
  • Murphy MSQ,* Ducharme R,* Hawken S, Corsi DJ, Petrcich W, El-Chaar D, Bisnaire L, McIsaac D, Fell DB, Wen SW, Walker MC. Maternal intrapartum epidural analgesia and risk of autism spectrum disorders in offspring: a retrospective cohort study from Ontario, Canada. 2022;5(5):e2214273. doi:10.1001/jamanetworkopen.2022.14273. *co-first authors who contributed equally to the project.  
  • Guo Y, Murphy MSQ, Erwin E, Fakhraei R, Corsi DJ, Rennicks White R, Harvey ALJ, Gaudet LM, Walker MC, Wen SW, El-Chaâr D. Outcomes of Cesarean Delivery on Maternal Request: A Population-Based Cohort Study. 2021. CMAJ. 193(18):E634-E644. doi: 10.1503/cmaj.202262