Previous Cesarean Section (VBAC)
Management of pregnancy after a prior cesarean section centers on the choice between a Trial of Labor After Cesarean (TOLAC) and an Elective Repeat Cesarean Section (ERCS).
Key Considerations
- TOLAC: The process of labor in a patient with a prior cesarean delivery. Success results in a Vaginal Birth After Cesarean (VBAC).
- Risk: The primary concern is uterine rupture, which occurs in approximately 0.5%–1% of patients attempting TOLAC with a low transverse incision.
- Contraindications for TOLAC: Prior classical uterine incision (vertical incision in the upper uterine segment), prior uterine rupture, or other contraindications to vaginal delivery (e.g., placenta praevia).
Factors Influencing Success
| Positive Predictors | Negative Predictors |
|---|---|
| Prior vaginal delivery. | Induction of labor (higher rupture risk). |
| Spontaneous labor. | Recurrent indication for the first CS (e.g., CPD). |
High-Yield Exam Pearl:
- Infrastructure: TOLAC should only be attempted in institutions with immediate availability of emergency cesarean section and neonatal resuscitation.
- Uterine Rupture Signs: The most common sign is a non-reassuring fetal heart rate pattern, often accompanied by loss of fetal station or intense abdominal pain.