VBAC Success — Grobman MFMU Calculator (Bands)
Predicts likelihood of successful vaginal birth after caesarean (TOLAC) using maternal age, BMI, prior vaginal delivery, prior VBAC, and indication for prior CS (Grobman 2007; race-free recalibration 2021). Use the live MFMU online tool for individualised %; this calculator records the band.
Score interpretation
→ Offer TOLAC per RCOG GTG 45. Plan birth in obstetric unit with continuous EFM, IV access, blood available, immediate access to caesarean. Avoid prostaglandin induction.
→ Detailed counselling on benefits and risks (uterine rupture ~0.5%, maternal/neonatal outcomes). Document shared decision; if VBAC chosen, plan as above with low threshold for ELCS in labour.
→ Counsel that ERCS may be the safer option. Review reasons for prior CS; consider individualised factors (BMI, age, prior failure to progress). Offer ELCS at 39+0 weeks.
Interpretation bands for the VBAC Success. Apply clinical judgement and local guidance.
References
Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.