VBAC Success Probability (MFMU, Grobman 2021)
Predicted chance of vaginal birth after caesarean for a trial of labour at term after one previous low-transverse caesarean (MFMU model without race or ethnicity, Grobman 2021), from information available at the first antenatal visit.
Score interpretation
Below 70 % predicted success, maternal morbidity with a trial of labour was higher than with elective repeat caesarean (RR 2.2; Grobman 2009).
→ Counsel on both options and document a shared decision. If VBAC is chosen: birth in an obstetric unit with continuous CTG, IV access and immediate access to caesarean (RCOG GTG 45); uterine rupture risk about 0.5 %.
At 70 % or more predicted success, maternal morbidity with a trial of labour was not higher than with elective repeat caesarean (Grobman 2009).
→ VBAC is a reasonable option if there are no contraindications. Birth in an obstetric unit with continuous CTG and immediate access to caesarean (RCOG GTG 45); uterine rupture risk about 0.5 %.
Interpretation bands for the VBAC Success. Apply clinical judgement and local guidance.
References
- Grobman WA, et al. Prediction of vaginal birth after cesarean delivery in term gestations: a calculator without race and ethnicity. Am J Obstet Gynecol. 2021;225(6):664.e1–664.e7.
- Grobman WA, et al. Can a prediction model for vaginal birth after cesarean also predict the probability of morbidity related to a trial of labor? Am J Obstet Gynecol. 2009;200(1):56.e1–56.e6.
- RCOG Green-top Guideline No. 45. Birth After Previous Caesarean Birth. 2015.
Related
Curated clinical cross-links plus same-class fallbacks.
- Hydroxyprogesterone Caproate / Progesterone (Preterm Birth Prevention) · Progestogen (Preterm Birth Prevention)
- Clotrimazole · Topical / vaginal imidazole antifungal
- Estradiol (HRT — Hormone Replacement Therapy) · Oestrogen Replacement Therapy
- Progesterone (Vaginal) · Progestogen
- Metronidazole (Bacterial Vaginosis) · Antibiotic (Nitroimidazole) — BV Treatment
- Clotrimazole (Vulvovaginal Candidiasis) · Antifungal (Azole) — Topical/Vaginal
- Spinal Anaesthesia Hypotension Management · AAGBI; ASA
- Pre-Eclampsia / Eclampsia in ED · NICE NG133; RCOG Green-top 10A
- Suspected Ectopic Pregnancy · NICE NG126; RCOG Green-top 21
- Polycystic Ovary Syndrome (PCOS) · International PCOS Guideline 2023; NICE CKS
- Pre-eclampsia Management · NICE NG133 2019
- Ectopic Pregnancy · NICE CG154 / RCOG GTG 21
Decision support only — verify against a current formulary, NICE, or your local guideline before clinical use.