The VBAC score calculator is designed to assess the likelihood of a successful vaginal birth after a previous Cesarean delivery by evaluating five key factors related to a woman's medical and delivery history. Each factor is assigned a specific numerical value based on predefined criteria, which collectively contribute to a total score. This score serves as an indicator of the probability of successfully having a vaginal birth after a Cesarean.

The scoring criteria for each factor are as follows:

- Maternal age less than 40 years: 
  - Yes: 2 points
  - No: 0 points

- Vaginal birth history: 
  - Vaginal birth before and after the first cesarean delivery: 4 points
  - Vaginal birth after the first cesarean delivery: 2 points
  - Vaginal birth before the first cesarean delivery: 1 point
  - No previous vaginal birth: 0 points

- Reason for first cesarean delivery other than failure to progress:
  - Yes: 1 point
  - No: 0 points

- Cervical effacement at admission:
  - Greater than 75%: 2 points
  - Between 25% and 75%: 1 point
  - Less than 25%: 0 points

- Cervical dilation of 4 cm or more at admission:
  - Yes: 1 point
  - No: 0 points

The total score is the sum of the points from each factor, with a possible range from 0 to 10. This total score translates into the probability of a successful VBAC, as interpreted below:

- A score between 0 and 2 suggests a 49% chance of successful VBAC.
- A score of 3 indicates a 60% probability.
- A score of 4 corresponds to a 67% probability.
- A score of 5 signifies a 77% probability.
- A score of 6 suggests an 88% probability.
- A score of 7 corresponds to a 93% probability.
- A score of 8 or higher indicates a 95% probability of success.

The calculator provides both the computed score and its corresponding interpretation to give a clear understanding of the likelihood of a successful vaginal birth after Cesarean, enabling informed decision-making.

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)