Risk of Uterine Rupture with Classical C-Section
The risk of uterine rupture following a classical cesarean section is approximately 1% in subsequent pregnancies, even without a trial of labor, which is significantly higher than the risk associated with low transverse cesarean sections. 1
Understanding Uterine Rupture Risk by Cesarean Type
Classical Cesarean Section
Classical cesarean sections involve a vertical incision in the contractile portion of the uterus (corpus) and carry specific risks:
- Subsequent pregnancy rupture risk: 1% even without labor 1
- Contraindication: Women with prior classical cesarean are contraindicated for trial of labor in subsequent pregnancies 2
- Comparison: This risk is substantially higher than with low transverse incisions
Low Transverse Cesarean Section
For comparison, low transverse cesarean sections have lower rupture risks:
- Planned repeat cesarean: 0.09% risk of uterine rupture 3
- Vaginal birth after cesarean (VBAC): 0.87% risk of uterine rupture 3
Risk Factors That Increase Uterine Rupture Risk
Several factors can further increase the risk of uterine rupture beyond the baseline risk associated with the type of incision:
- Previous uterine rupture 4
- Labor induction (especially with prostaglandins) 4
- Multiple previous cesarean sections 4
- Fetal macrosomia 4
- Short interpregnancy interval (<6 months) 4
- Lower resource settings: Risk is higher in low-HDI countries (1.0%) compared to high-HDI countries (0.2%) 5
- Lower maternal education level (≤6 years) increases risk (AOR 1.71) 5
Maternal and Fetal Outcomes of Uterine Rupture
Maternal Outcomes
- Mortality: <1% maternal mortality 4
- Severe morbidity: 15% of cases 4
- Increased risk of death: 4.45 times higher risk of maternal death with uterine rupture 5
Fetal/Neonatal Outcomes
- Mortality at term: 3-6% 4
- Perinatal asphyxia: 6-15% 4
- Increased risk of death: 33.34 times higher risk of perinatal death with uterine rupture 5
Management Implications for Future Pregnancies
For women with a history of classical cesarean section:
- Repeat cesarean delivery is recommended for subsequent pregnancies due to the high risk of recurrent uterine rupture 4, 2
- Trial of labor is contraindicated after a classical cesarean section 2
- Timing: Scheduled cesarean delivery before the onset of labor is important, as labor increases rupture risk 3
Caveat and Clinical Considerations
- The vertical incision in the contractile corpus makes uterine closure technically difficult and increases risk of hemorrhage and adhesions 2
- Uterine rupture diagnosis relies on a combination of severe pathologic patterns of fetal heart monitoring with unusual pelvic pain 4
- Suspected uterine rupture requires expedited laparotomy 4
The significantly higher risk of uterine rupture with classical cesarean section underscores the importance of careful planning for subsequent pregnancies and appropriate counseling about the risks involved.