Vaginal Birth after Cesarean

Decreased success rate (associated with <60% successful VBAC)
1. More then 2 cesarean deliveries without a prior Vaginal Delivery
2. Prior cesarean delivery for failure to descend in the Second Stage of Labor
3. Labor Induction needed
4. Fetus >4000 grams
5. Maternal Body Mass Index >40 kg/m2
6. Maternal age over 35 years old
Neutral success rate (associated with 65-75% successful VBAC)
1. Gestational age >40 weeks
2. Prior cesarean delivery for nonreassuring Fetal Heart Tones
3. Prior cesarean delivery for Failure to Progress in the First Stage of Labor
4. Unknown uterine scar type
5. Twin Gestation
6. Labor Augmentation
7. Two prior cesarean deliveries with prior Vaginal Delivery
8. Maternal Body Mass Index 25-40 kg/m2
Increased success rate (associated with >75% successful VBAC)
1. Prior successful Vaginal Birth
2. Maternal BMI <25 kg/m2
3. Prior cesarean delivery for Breech Presentation
4. Spontaneous labor with Cervix determined to be ripe by Bishop Score
5. Maternal age <35 years old
References
1. Leeman (2008) Obstet Gynecol Clin North Am 35(3): 473-95 +PMID:18760231 [PubMed]

One or two prior low-transverse Cesarean Sections
Adequate Pelvis for delivery
No contraindication (see above)
Physician immediately available during active labor
1. Capable of monitoring labor
2. Immediate cesarean delivery available

Conditions
1. One prior low-transverse Cesarean Sections
2. Spontaneous onset of labor
3. No need of augmentation
4. No repetitive Fetal Heart Rate abnormalities
5. Prior successful Vaginal Birth after Cesarean delivery
Management
1. Provider responsible for cesarean delivery (backup) may have other acute care responsibilities

Conditions
1. Labor Induction
2. Oxytocin Augmentation
3. Three or more prior low transverse cearean sections
4. Last cesarean delivery was less than 18 months from the current delivery
Management
1. Provider responsible for cesarean delivery (backup)
  1. Must be present in the hospital during the Active Phase of Labor
  2. May have other in-hospital acute care responsibilities
2. Operating room
  1. Open and staffed operating room available for emergency cesarean OR
  2. Other room available with adequate lighting where general Anesthesia may be administered
3. Anesthesia
  1. Anesthesia provider is in hospital during the Active Phase of Labor
  2. May have other in-hospital acute care responsibilities
  3. Established back-up protocol when Anesthesia is busy with other responsibilities

Conditions
1. Repetitive nonreassuring Fetal Heart Rate abnormalities refractory to interventions
2. Vaginal Bleeding suggestive of Placental Abruption
3. Labor Dystocia
  1. Two hours without cervical change in the active phase despite adequate labor
Management
1. Provider responsible for cesarean delivery (backup)
  1. Must be present in the hospital during the Active Phase of Labor
  2. May have NO other acute patient responsibilities
2. Anesthesia
  1. Anesthesia provider is in hospital during the Active Phase of Labor
  2. May have NO other in-hospital acute care responsibilities
3. Operating room
  1. Open and staffed operating room available for emergency cesarean

Facilities performing TOLAC should have emergency cesarean delivery available
Cervical Ripening Agents (Prostaglandins) have higher risk of rupture
1. Contraindicated in TOLAC patients
Measures that are considered safe (with caution) in TOLAC
1. Cervical Ripening Balloons
2. Oxytocin (Pitocin)

Uterine Rupture or Uterine Scar Dehiscence (38 per 10,000 trials of labor)
1. See Uterine Rupture for risks
Perinatal death (1.4 per 10,000 trials of labor)
1. Similar risk to Vaginal Delivery risk
2. Contrast with 0.5 per 1000 births with elective repeat cesarean delivery
Hysterectomy (3.4 per 10,000 trials of labor)
References
1. Guise (2004) BMJ 329:19-25 [PubMed]