What are the indications for a classical C-section (cesarean section)?

Classical Cesarean Section Indications

A classical cesarean section (vertical incision in the upper uterine segment) is indicated when access to the lower uterine segment is difficult or unsafe, specifically in cases of extreme prematurity, dense lower segment adhesions, placenta previa/accreta involving the lower segment, and certain gynecologic malignancies obstructing the birth canal. 1

Primary Indications

Anatomical Access Limitations

• Preterm delivery when the lower uterine segment is poorly developed, making a low transverse incision technically difficult or risky for fetal injury 1
• Dense adhesions from prior surgeries that prevent safe access to the lower uterine segment 1
• Placenta previa or placenta accreta involving the lower uterine segment, where a corporeal incision avoids the placental bed 1

Oncologic Indications

• Cervical cancer requiring cesarean delivery, where a corporeal uterine incision avoids surgical trauma to the lower uterine segment harboring the malignancy and prevents tumor implantation in the hysterotomy site 2
• Vulvar cancers obstructing the birth canal may also necessitate cesarean delivery with consideration of classical incision depending on lower segment involvement 2

Emergency Situations

• Maternal cardiac arrest at ≥20 weeks gestation (when fundus reaches umbilicus) where perimortem cesarean section is indicated, and classical incision may provide fastest fetal delivery if lower segment access is compromised 2
• The hysterotomy should ideally begin approximately 4 minutes after onset of maternal cardiac arrest to achieve delivery within 5 minutes 2

Technical Considerations

Surgical Technique

• Classical incision allows smooth and gentle delivery of the fetus, particularly important in preterm deliveries 1
• However, uterine closure is technically more difficult than low transverse closure, requiring speedy and skillful technique to minimize hemorrhage and adhesion formation 1

Critical Risks

• Uterine rupture risk in subsequent pregnancies is substantially elevated (1-12% based on published reports) compared to low transverse incision 3, 4
• The risk of spontaneous uterine rupture without trial of labor is approximately 1% in subsequent pregnancies 4
• Trial of labor after cesarean (TOLAC) is absolutely contraindicated following classical cesarean section 1

Management of Subsequent Pregnancies

Delivery Timing

• Scheduled cesarean delivery at 36-37 weeks gestation is recommended for patients with prior classical cesarean section to optimize maternal and fetal outcomes before spontaneous labor onset 3
• This earlier timing balances the risk of uterine rupture against neonatal prematurity complications 3

Monitoring Requirements

• Detailed ultrasound evaluation should be performed in early pregnancy to confirm proper implantation and assess for cesarean scar pregnancy 5
• Patients require counseling about increased risks including recurrent cesarean scar pregnancy, placenta accreta spectrum, and uterine rupture 5

Common Pitfalls to Avoid

• Do not delay classical incision when indicated—attempting to force a low transverse incision in unfavorable anatomy increases maternal and fetal morbidity 1
• Do not allow trial of labor in subsequent pregnancies after classical cesarean section, regardless of patient preference 1
• Do not wait beyond 36-37 weeks for scheduled delivery in subsequent pregnancies, as uterine rupture risk increases with advancing gestational age and onset of labor 3
• In oncologic cases, ensure the incision avoids the tumor-bearing lower segment to prevent metastatic implantation in the surgical wound 2