BACKGROUND AND PURPOSE: 

• Shinar et al. (AJOG, 2021) assessed the maternal and neonatal risks associated with elective delivery at different gestational ages vs expectant management among women with at least 2 previous cesarean deliveries 

METHODS: 

• Retrospective, population-based cohort study 
  • Ontario, Canada between April 2012 and March 2019 
• Population 
  • ≥2 previous cesarean deliveries who delivered after 36w6d  
  • Exclusions: Multifetal pregnancies or major fetal anomalies  
• Exposure 
  • Elective cesarean (at completed gestational weeks) 
    • Expectant management 
• Study design 
  • For each completed gestational week 
    • Outcomes of elective repeat cesarean delivery at particular week were compared to expectant management  
    • Only indication for previous delivery was history of 2 previous cesarean deliveries  
• Primary outcome 
  • Composite of maternal outcomes including mortality and severe maternal morbidity 
• Secondary outcomes 
  • Adverse neonatal outcomes 

RESULTS: 

• 26,522 women 
• Compared to expectant management beyond the specified week, incidence of the composite maternal outcome for elective delivery was similar for the following weeks 
  • 37w0d to 37w6d 
  • 38w0d and 38w6d  
• Elective delivery between 39w0d and 39w6d was associated with a lower risk for composite maternal adverse outcome vs expectant management from 40w0d gestation  
  • 2.1% vs 3.2%; P=.02 
  • Adjusted risk ratio (aRR) 0.51 (95% CI, 0.29 to 0.91) 
• Compared to ongoing pregnancy, the risk of adverse neonatal outcomes significantly increased with elective delivery during the 37th week of gestation  
  • aRR 1.68 (95% CI, 1.39 to 2.01) 
• Risk of adverse neonatal outcomes was similar to the risk with expectant management when elective cesarean was performed at 38w0d to 39w6d  
• The risk for an unplanned cesarean delivery increased over gestational time 
  • <38 weeks: 6.5%  
  • <39 weeks: 21.7%  
  • <40 weeks: 32.6%  

CONCLUSION: 

• For women with more than 2 previous cesareans, the best time for elective cesarean delivery is probably between 38w0d to 38w6d 
• The authors state 

…delivery during the 39th week will lead to a greater proportion (nearly a third) of unplanned deliveries than with delivery during the 38th week 

Elective CD during the 37th week of gestation should be avoided because of the increased neonatal risk 

Therefore, to minimize the likelihood of unplanned delivery without increasing maternal and neonatal risk associated with delivery at a certain gestational age, we recommend delivery during the 38th week of gestation 

Learn More – Primary Sources: 

Timing of cesarean delivery in women with ≥2 previous cesarean deliveries 

Related ObG Topics:

Delivery at 37 or 39 Weeks for Higher Order Cesarean Sections?

Three Previous Cesarean Deliveries: When to Deliver?

Classical Cesarean Incision: Delivery at 36 vs 37 Weeks