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Obstetrics and gynaecology

VBAC Success Prediction

6 inputsObstetrics and gynaecology

Estimated probability of successful vaginal birth after caesarean.

VBAC Success Prediction calculator

Result

~64%

Moderate probability — detailed counselling

Simplified model. Metz-Saade VBAC score or eMBRACE calculator more precise.

Maternal BMI

15 to 50 years

How to use it

  1. 1

    Key success factors. Prior vaginal birth (strongest), non-recurrent indication, spontaneous labour, BMI < 30.

  2. 2

    Counselling. VBAC success ~72–75% overall. Risk of uterine rupture ~0.5%.

  3. 3

    Use validated online calculators. MFMU Network VBAC calculator (maternal-fetal.net) gives personalised probability using regression model.

When to use it

Planning mode of delivery with prior CS
NICE CS2023: planned VBAC is appropriate for most women with single prior LSCS.
Informed consent
Discuss success probability, uterine rupture risk, and risks of elective repeat CS.
Two prior CS
Lower success rate (~65%), higher rupture risk — more individualised counselling required.

A reference for clinicians and students, not medical advice. A score supports a decision; it does not make one. Check every result against the patient in front of you and your local protocol.

At a glance

Specialty
Obstetrics and gynaecology
Inputs
6
Type
Formula

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