BACKGROUND AND PURPOSE:

• Guidline for delivery for prior classical cesarean: 36w0d – 37w0d  (ACOG/SMFM)
• Ma’ayeh et al. (Am J Perinatol, 2020) compared neonatal outcomes for delivery at 36 weeks vs 37 weeks in women with prior classical cesarean delivery (CCD)

METHODS:

• Secondary analysis of a prospective observational cohort
  • MFMU Network Cesarean Registry | 19 US hospitals between 1999 and 2003
• Participants
  • Cesarean birth or TOLAC
• Exposures
  • Delivery at 36w0d to 36w6d
  • Delivery at 37w0d to 37w6d
• Primary outcome
  • Composite of adverse neonatal outcomes (including): NICU admission | RDS | Transient tachypnea of the newborn | Hypoglycemia | Mechanical ventilation | Sepsis | Length of stay ≥5 days | Neonatal death
  • Composite of maternal outcomes (including): Uterine rupture | Blood transfusion | General anesthesia | Cesarean hysterectomy | VTE | Maternal sepsis | ICU | Surgical complication

RESULTS:

• 436 patients
  • Delivered at 36 weeks: 176 patients
  • Delivered at 37 weeks: 260 patients
• Delivery at 37 weeks was associated with a
  • Reduction in composite neonatal morbidity
    • Delivery at 36 weeks: 34%
    • Delivery at 37 weeks: 24%
    • Adjusted odds ratio (aOR) 0.61 (95% CI, 0.31 to 0.94)
  • Decrease in NICU admission rates
    • Delivery at 36 weeks: 29%
    • Delivery at 37 weeks: 20%
    • aOR 0.63 (95% CI, 0.40 to 0.99)
  • Decrease in hospitalizations ≥5 days
    • Delivery at 36 weeks: 24%
    • Delivery at 37 weeks: 13%
    • aOR 0.48 (95% CI, 0.29 to 0.8)
  • Decrease in RDS and transient tachypnea of the newborn
    • Delivery at 36 weeks: 19%
    • Delivery at 37 weeks: 9%
    • aOR 0.43 (95% CI, 0.24 to 0.77)
• There were no differences in adverse maternal outcomes
  • Delivery at 36 weeks: 7%
  • Delivery at 37 weeks: 7%
  • aOR 0.98 (95% CI, 0.46 to 2.09)

CONCLUSION:

• For women with a classical cesarean incision, delivery at 37 weeks was linked to fewer adverse neonatal outcomes vs delivery at 36 weeks with no significant differences in maternal outcomes
• The authors acknowledge that the study was not sufficiently powered to detect uterine rupture as an isolated outcome due to sample size and rarity of the event  

Learn More – Primary Sources:

Timing of Repeat Cesarean Delivery for Women with a Prior Classical Incision

Related ObG Topics:

Classical vs Transverse Uterine Incision for Preterm Birth

Three Previous Cesarean Deliveries: When to Deliver?

What are Risk Factors Associated with Complete Uterine Rupture?