What are the indications for cesarean (C-) sections?

Indications for Cesarean Section

Cesarean section is indicated for specific maternal, fetal, and obstetric conditions where vaginal delivery poses unacceptable risks to maternal or fetal survival and wellbeing.

Absolute Maternal Indications

Maternal cardiac conditions requiring cesarean section include:

• Severe pulmonary hypertension 1
• Significant aortopathy (aortic diameter >45 mm in Marfan syndrome) 2
• Acute maternal cardiac instability or heart failure 1
• Maternal cardiac arrest (delivery within 5 minutes of arrest onset to optimize maternal resuscitation and fetal survival) 3, 1

Other critical maternal indications:

• Women on anticoagulation therapy (particularly warfarin) to minimize time off anticoagulation and reduce valve thrombosis risk 1
• Acute fatty liver of pregnancy (AFLP) or HELLP syndrome, where cesarean section improves maternal and perinatal outcomes 1
• Anticipated difficult airway to avoid emergency general anesthesia 1

Infectious Disease Indications

HIV-positive women with viral load >1,000 copies/mL near delivery time require scheduled cesarean section at 38 completed weeks of gestation, regardless of antiretroviral therapy type 1, 2. Intravenous zidovudine should be started at least 3 hours before surgery, and the woman's prenatal antiretroviral regimen must not be interrupted 1.

For hepatitis B, cesarean section is not routinely recommended except in Asian HBeAg-positive women with high HBV DNA titre (>7 log₁₀ copies/ml; 6.14 log₁₀ IU/ml) who have not received antiviral therapy during pregnancy 3.

Hepatitis C with high viral load may warrant cesarean section to reduce vertical transmission risk 1.

Hepatitis A does not require cesarean section unless there is an obstetric indication 3.

Fetal Indications

Immediate cesarean section is required for:

• Fetal distress with irreversible causes including major placental abruption, fetal hemorrhage, and umbilical cord prolapse with sustained bradycardia 1, 4
• Delivery should occur within 25 minutes of sustained fetal bradycardia to improve long-term neonatal neurologic outcome 5

Fetal growth restriction with:

• Abnormal Doppler studies (absent or reversed end-diastolic flow in umbilical artery) warrants cesarean section by 32-34 weeks 1
• Abnormal fetal surveillance including abnormal cardiotocography or ductus venosus Doppler 1

Obstetric Indications

The four major obstetric indications accounting for most cesarean sections are:

• Previous cesarean section (particularly classical/vertical incision, which is an absolute contraindication to trial of labor) 6, 7
• Dystocia (failure to progress in labor) 7
• Breech presentation (elective cesarean at 38 weeks) 4
• Fetal distress 7, 8

Additional obstetric scenarios:

• Dense pelvic adhesions preventing safe access to lower uterine segment 6
• Placenta previa or accreta requiring vertical hysterotomy 6
• Preterm labor where lower uterine segment access is difficult 6

Emergency Situations Requiring Immediate Cesarean Section

When a woman with planned cesarean section presents in early labor or with ruptured membranes:

• If cervical dilation is minimal and long labor is anticipated, proceed with cesarean section to minimize membrane rupture duration 3
• If labor is progressing rapidly, allow vaginal delivery 3
• If membranes have been ruptured >4 hours, the benefit of cesarean section becomes unclear 3
• Intravenous medications should be started immediately while assessing the situation 3, 4

Critical Timing Considerations

For maternal cardiac arrest: Peripartum cesarean section must be performed within 5 minutes of arrest onset—not only for maternal resuscitation but for neonatal survival 3, 5. No maternal survival has been reported after 15 minutes of resuscitation, and no fetal survival after 30 minutes 3.

For sustained fetal bradycardia: Delivery within 25 minutes improves long-term neonatal neurologic outcomes 5.

Important Caveats and Pitfalls

Avoid unnecessary cesarean sections: Approximately half of cesareans performed in the U.S. may be medically unnecessary, resulting in avoidable maternal mortality and morbidity 7. Maternal mortality is 2-4 times higher and morbidity is 5-10 times higher after cesarean compared to vaginal birth 7.

Long-term risks of cesarean section include:

• Chronic wound pain (15.4% at 3-6 months postpartum) 1, 2
• Increased risk of placenta previa and accreta in subsequent pregnancies 1, 2
• Uterine rupture in subsequent pregnancies (22 per 10,000 births) 1, 2
• Venous thromboembolism (2.6 per 1,000 cesarean births) 1, 2
• Secondary infertility (up to 43% of women) 1, 2
• Postpartum infections are 5-7 times more common after cesarean section 1, 2

Technical pitfalls during cesarean delivery:

• Improper disimpaction techniques causing fetal head hyperextension rather than flexion, increasing risk of skull fracture and neurological injury 4
• Inadequate hand positioning during vaginal "push" technique 4
• Lack of multidisciplinary team preparation and appropriate equipment availability 1, 4

Anesthetic considerations: Regional anesthesia (spinal or epidural) is strongly preferred over general anesthesia for most cesarean sections 1. General anesthesia can precipitate uncontrolled hypertension in preeclamptic women and carries higher maternal risks 1.