Updated January 28, 2015.

Wouldn't it be great that if you were planning a vaginal birth after cesarean (VBAC), you knew what your chances of a vaginal birth were?

We typically tell women that their chances are about 87% of having a vaginal birth. Well, now there is a new study that says, once labor has begun, we have a pretty good chance of predicting a vaginal birth, based on a scoring system.

Over 5,000 women were broken into two groups, in a records review.

The first group was used to develop the scoring system, using the admission status of several factors. The second group was tested upon that scoring system and rated on the chances of VBAC.

The scoring criteria were based on:

• Age of the Mother
• Vaginal Birth History
• Reason other than lack of progress for first cesarean
• Cervical effacement at the time of admission
• Cervical dilation of more than 4 cm at the time of admission

The scale is based on a highest score of 10. The 0 - 2 range had a 49% VBAC rate, while the 8 - 10 group had a 95% VBAC rate.

There was a high correlation of a vaginal birth prior to the cesarean and after the cesarean, enough to give the woman four points towards the score of 10. Although only three percent of the women had that history. In fact, 70% had no history of prior vaginal birth.

The authors of the study hope to find variables that can be corrected in dysfunctional labors in a hopes to prevent further cesarean surgeries.

This study can be read in its entirety:
"Vaginal Birth After Cesarean: An Admission Scoring System," by Bruce L. Flamm, MD, and Ann M. Geiger, PhD. Obstetrics & Gynecology, 90(6):907-910, December 1997.