Maternal Age

Age ≥ 40 years (0 pts)+0Age < 40 years (+2 pts)+2

Any Prior Vaginal Delivery

No prior vaginal deliveries+0Prior vaginal delivery (either pre- or post-CS) (+2 pts)+2

Previous Cesarean Indication

Prior CS for recurring indication (e.g., CPD, failure to progress, brow/face, or unknown) (+0 pts)+0Prior CS for non-recurring indication (e.g., fetal malpresentation, placenta previa, NRFHR) (+1 pt)+1

Cervical Effacement at Admission

< 25% effaced (+0 pts)+025–75% effaced (+1 pt)+1> 75% effaced (+2 pts)+2

Cervical Dilation at Admission (cm)

< 4 cm dilated (+0 pts)+0≥ 4 cm dilated (+1 pt)+1

Spontaneous Labor (vs. Induced)

Induced labor (+0 pts)+0Spontaneous labor (+1 pt)+1

Self-Reported Race/Ethnicity

Other (+1 pt)+1African American or Hispanic (+0 pts)+0

VBAC Success Prediction Score (Flamm Model)

VBAC Success Prediction Score (Flamm Model)