While the choice for how to bring a child into the world is deeply personal, the data paints a compelling picture: for most women with one prior cesarean, planning a VBAC carries a 60-80% success rate alongside significantly lower risks of maternal complications and a faster recovery compared to a repeat surgical delivery.
Key Takeaways
- Overall VBAC success rate is 60-80% for women with one prior low transverse cesarean incision
- VBAC success rate reaches 91% for women with one prior vaginal delivery and one prior cesarean
- Spontaneous labor onset correlates with 75-85% VBAC success compared to 50-65% with induction
- Uterine rupture risk is 0.5-0.9% for women with one prior low transverse cesarean attempting VBAC
- Risk of uterine rupture increases to 1.8-3.7% with prostaglandin induction for VBAC
- Oxytocin use raises rupture risk to 1.0-1.5% vs 0.6% without
- VBAC transfusion risk 1.5% vs 2.8% repeat cesarean
- Hysterectomy risk 0.4% after uterine rupture in VBAC
- Maternal infection rate 4.2% VBAC vs 8.1% repeat cesarean
- NICU admission 4.9% VBAC vs 7.2% elective repeat cesarean
- Perinatal mortality 1.1/1,000 VBAC vs 1.2/1,000 repeat cesarean
- Hypoxic-ischemic encephalopathy 0.15% VBAC rupture cases
- Prior vaginal birth increases VBAC success by 2-3 fold (OR 2.5)
- Spontaneous labor most favorable predictor (success OR 3.2)
- Shorter stature (<155cm) reduces success (OR 0.6)
VBAC success is likely for most mothers with a prior cesarean.
Fetal Neonatal Outcomes
- NICU admission 4.9% VBAC vs 7.2% elective repeat cesarean
- Perinatal mortality 1.1/1,000 VBAC vs 1.2/1,000 repeat cesarean
- Hypoxic-ischemic encephalopathy 0.15% VBAC rupture cases
- 5-minute Apgar <7: 1.8% VBAC vs 2.5% cesarean
- Neonatal sepsis 1.2% VBAC vs 2.1% repeat cesarean
- Meconium aspiration 0.8% VBAC vs 1.4% cesarean
- Umbilical cord pH <7.0: 0.9% after rupture
- Respiratory distress syndrome 2.3% VBAC vs 3.8% cesarean
- Birth asphyxia 0.3% VBAC vs 0.5% elective repeat
- Neonatal transfusion 0.4% VBAC vs 1.1% cesarean
- Long-term neurodevelopmental issues no difference (OR 1.02)
- Cerebral palsy risk 0.12% VBAC vs 0.15% cesarean
- Jaundice requiring phototherapy 5.2% VBAC vs 6.8% cesarean
- Shoulder dystocia 1.5% VBAC vs 0.2% cesarean
- Brachial plexus injury 0.2% VBAC post-dystocia
- NICU >3 days 2.1% VBAC vs 4.3% cesarean
- Transient tachypnea newborn 3.1% VBAC vs 5.9% cesarean
- Fetal distress leading to cesarean 12% VBAC attempts
- Neonatal death 0.15/1,000 VBAC vs 0.18/1,000 repeat
- Hypoglycemia 4.5% VBAC vs 6.2% cesarean
- Ventilator support 0.5% VBAC vs 1.2% cesarean
- Intracranial hemorrhage 0.05% rupture cases
- Breastfeeding exclusivity higher 65% VBAC vs 55% cesarean at 6 months
Fetal Neonatal Outcomes Interpretation
While the slightly higher odds of shoulder dystocia during a VBAC are real, the overall neonatal ledger reads like a compelling case for letting a proven pelvis have another go, given the consistently lower rates of NICU vacations, respiratory distress, infections, and jaundice, plus a bonus for breastfeeding, all with no long-term brain development downside.
Influencing Factors
- Prior vaginal birth increases VBAC success by 2-3 fold (OR 2.5)
- Spontaneous labor most favorable predictor (success OR 3.2)
- Shorter stature (<155cm) reduces success (OR 0.6)
- Recurrent indication halves success odds (OR 0.5)
- Maternal age >35 years decreases success (OR 0.7)
- BMI >30 kg/m² lowers odds (OR 0.4 per 5-unit increase)
- Gestational diabetes reduces success (OR 0.65)
- Estimated fetal weight >4000g decreases OR 0.55
- Labor induction lowers success (OR 0.4)
- Provider counseling increases attempt rate 25%
- Hospital VBAC rate >15% boosts individual success 10%
- Interdelivery interval >18 months OR 1.4 success
- Cervical Bishop score ≥6 predicts 85% success
- Ethnicity influences: Asian OR 1.2 success
- Insurance status: private OR 1.3 vs public
- Prior postpartum hemorrhage OR 0.7 success
- Ultrasound EFW accuracy <10% error OR 1.5 success
- Continuous EFM availability increases attempts 30%
- Midwife-led care OR 2.1 VBAC success
- Smoking status no effect (OR 0.95)
- Parity ≥2 OR 1.8 success
- Vertex presentation OR 3.0 vs breech
- No preeclampsia history OR 1.2 success
- Labor support doula OR 1.6 success
- Outpatient antenatal education increases attempts 40%
Influencing Factors Interpretation
When plotting your VBAC journey, remember you're more likely to sail through with a prior vaginal birth and spontaneous labor, but be prepared to navigate headwinds like induction, a larger baby, or a higher BMI, though a skilled crew—like a supportive provider, accurate ultrasounds, and a doula—can significantly improve your odds of reaching the desired destination.
Maternal Outcomes
- VBAC transfusion risk 1.5% vs 2.8% repeat cesarean
- Hysterectomy risk 0.4% after uterine rupture in VBAC
- Maternal infection rate 4.2% VBAC vs 8.1% repeat cesarean
- Postpartum hemorrhage 2.3% VBAC vs 6.1% elective repeat
- Maternal mortality 3.8/100,000 VBAC vs 13.3/100,000 cesarean
- Shorter hospital stay: 2.1 days VBAC vs 3.7 days cesarean
- Breastfeeding initiation 85% VBAC vs 75% cesarean
- Maternal satisfaction 94% with successful VBAC
- Thromboembolism 0.3% VBAC vs 1.2% cesarean
- Wound infection 1.5% VBAC vs 9.8% cesarean
- Readmission rate 2.1% VBAC vs 4.5% cesarean within 30 days
- Severe morbidity composite 13.3% VBAC vs 24.5% repeat cesarean
- Pain scores lower at 6 weeks postpartum in VBAC group (2.1 vs 4.3)
- Maternal ICU admission 0.2% VBAC vs 0.9% cesarean
- Depression screening positive 12% VBAC vs 18% cesarean
- Faster return to work: 4 weeks VBAC vs 6 weeks cesarean
- Operative injury risk 1.8% VBAC vs 3.4% cesarean
- Cost savings $1,800 per VBAC success vs repeat cesarean
- Pelvic floor dysfunction 15% less in VBAC at 1 year
- Blood transfusion 1-2% VBAC vs 3-5% repeat cesarean
- Endometritis 2.5% VBAC vs 7.2% cesarean
- Maternal fever during labor 10% VBAC vs 18% induced cesarean
- Long-term adhesion risk lower 5% VBAC vs 20% multiple cesareans
- VBAC maternal death rate 0.4/100,000 vs 2.1/100,000 elective repeat
- Perineal laceration 3rd/4th degree 3.5% VBAC vs 0% cesarean
Maternal Outcomes Interpretation
While the path of a VBAC carries its own distinct risks, the data paints a surprisingly clear portrait: for most eligible mothers, it offers a markedly safer and more positive recovery journey than a repeat cesarean, with the notable caveat that success cannot be guaranteed.
Risks and Complications
- Uterine rupture risk is 0.5-0.9% for women with one prior low transverse cesarean attempting VBAC
- Risk of uterine rupture increases to 1.8-3.7% with prostaglandin induction for VBAC
- Oxytocin use raises rupture risk to 1.0-1.5% vs 0.6% without
- Classical uterine incision rupture risk 4-9% during TOLAC
- Two prior cesareans: rupture risk 1.8% for low transverse
- Maternal BMI >40 kg/m²: rupture risk 2.1% vs 0.7% normal BMI
- Inter-pregnancy interval <6 months: rupture risk 2.7%
- Prior vaginal delivery reduces rupture risk to 0.4%
- Fetal macrosomia (>4000g) increases rupture to 1.2%
- Labor >12 hours: rupture risk 1.3% vs 0.5% shorter
- External cephalic version: rupture risk 1.0%
- Placenta previa with VBAC: rupture risk 2.5%
- Age >40 years: rupture risk 1.6%
- Multiple gestation: rupture risk 2.0%
- Misoprostol use: rupture risk up to 5.1%
- Shoulder dystocia history: rupture risk 1.1%
- VBAC after 3+ cesareans: rupture 3.7%
- Epidural analgesia: rupture risk 0.8% (no increase)
- Gestational age >42 weeks: rupture 1.4%
- Prior uterine rupture: absolute contraindication, risk >20%
- Foley catheter induction: rupture 0.7%
- Black ethnicity: rupture risk 1.2% vs 0.7% white
- VBAC in preterm labor: rupture 0.9%
- Cervical ripening with dinoprostone: rupture 1.9%
- Labor arrest disorder: rupture 1.0%
Risks and Complications Interpretation
The data paints a nuanced picture: the foundational risk of uterine rupture during a VBAC is modest, but it's a chameleon, shifting in hue with your history, your body's current state, and the specific tools your medical team might use.
Success Rates
- Overall VBAC success rate is 60-80% for women with one prior low transverse cesarean incision
- VBAC success rate reaches 91% for women with one prior vaginal delivery and one prior cesarean
- Spontaneous labor onset correlates with 75-85% VBAC success compared to 50-65% with induction
- VBAC success rate is 72% in grand multiparous women (≥4 prior deliveries)
- For women <34 years old, VBAC success is 78%, rising to 82% under 30 years
- Inter-pregnancy interval >18 months yields 76% VBAC success vs 68% for shorter intervals
- Nonrecurring indication for prior cesarean boosts VBAC success to 85%
- VBAC success is 80% when prior cesarean was for fetal distress vs 65% for failure to progress
- Maternal BMI <30 kg/m² associated with 77% VBAC success vs 55% for BMI >35
- White race ethnicity shows 75% VBAC success vs 68% for Black women
- Public insurance correlates with 70% VBAC success vs 82% private
- Hospital VBAC attempt rate >20% per year yields 75% success
- VBAC success 84% with continuous labor support (doula)
- Singleton vertex presentation: 74% VBAC success
- Gestational age 39-40 weeks: 78% VBAC success
- No prior classical incision: 75% success rate
- VBAC success 70% in first-time mothers with prior cesarean
- Outpatient management success rate 80% for low-risk VBAC candidates
- Regional anesthesia use: 72% VBAC success
- VBAC success 85% after one prior successful VBAC
- Labor augmentation with oxytocin: 68% success
- VBAC success 76% in community hospitals vs 72% academic centers
- Hispanic ethnicity: 73% VBAC success rate
- Prior postpartum hemorrhage: 65% VBAC success
- VBAC success 81% with estimated fetal weight <4000g
- Nighttime admission: 74% success vs daytime 76%
- VBAC success 79% for women with prior uncomplicated cesarean
- Age 35-39 years: 70% VBAC success
- VBAC success rate 77% with cervical dilation >3cm on admission
- Trial of labor after two cesareans (TOLAC-2): 71% success
Success Rates Interpretation
The recipe for a successful VBAC appears to be a young, fit, privately-insured woman with a proven track record of pushing babies out, who goes into labor naturally at term with a small baby and a doula by her side, while avoiding inductions, obesity, and hospitals that seem skittish about the whole endeavor.
Sources & References
- Reference 1ACOGacog.orgVisit source
- Reference 2PUBMEDpubmed.ncbi.nlm.nih.govVisit source
- Reference 3NEJMnejm.orgVisit source
- Reference 4NCBIncbi.nlm.nih.govVisit source
- Reference 5JOURNALSjournals.lww.comVisit source
- Reference 6AJOGajog.orgVisit source
- Reference 7JAMANETWORKjamanetwork.comVisit source
- Reference 8CDCcdc.govVisit source
- Reference 9NICHDnichd.nih.govVisit source