The VBAC score, or Vaginal Birth After Cesarean section score, is a clinical calculator used in obstetrics. It is specifically designed for pregnant women who have had a previous cesarean section and are considering a trial of labor for their current pregnancy. The VBAC score helps to predict the likelihood of a successful vaginal delivery, which can aid in shared decision-making between the patient and healthcare provider. 

The score takes into account various factors including maternal age, body mass index (BMI), gestational age, history of vaginal delivery, and the indication for the previous cesarean section. The higher the score, the greater the likelihood of a successful vaginal birth after cesarean.

Exclusion criteria for the use of the VBAC score may include contraindications to vaginal delivery such as placenta previa, active herpes infection, or a transverse lie of the fetus. Additionally, it may not be applicable in cases where the previous cesarean section was performed due to a non-recurring indication (e.g., breech presentation).

Vaginal delivery after Cesarean section score (VBAC score)

# Criteria
 ## Maternal age < 40 years
A. Yes (+2)
B. No (+0)
## Vaginal birth history
C. Vaginal birth before and after first cesarean delivery (+4)
D. Vaginal birth after first cesarean delivery (+2)
E. Vaginal birth before first cesarean delivery (+1)
F. No previous vaginal birth (+0)
## Reason other than failure to progress for first cesarean delivery
G. Yes (+1)
H. No (+0)
## Cervical effacement at admission
I. > 75% (+2)
J. 25-75% (+1)
K. < 25% (+0)
## Cervical dilation >= 4 cm at admission
L. Yes (+1)
M. No (+0)

# Conditions
- score <= 2
- score == 3
- score == 4
- score == 5
- score == 6
- score == 7
- score >= 8
- score == 0