What does the research say about VBAC compared to repeat C-section?

If you do not have a clear and compelling need for a cesarean in your present pregnancy, having a VBAC rather than a repeat C-section is likely to be:

  • Safer for you in this pregnancy
  • Much safer for you and your babies in any future pregnancies

When thinking about the health and safety of your baby in your current pregnancy, there are trade-offs to consider: VBAC has some advantages, and a repeat C-section has others. Despite limitations of the best available research, the following conclusions seem clear:

  • The scar is more likely to give way during a VBAC labor than in a repeat C-section, but this risk is low. A uterine rupture will occur about once in every 238 labors after C-section.Guise, J.M., Eden, K., Emeis, C., . . . McDonagh, M. (2010). Vaginal birth after cesarean: New insights. Evidence Report/Technology Assessment No.191. (Prepared by the Oregon Health & Science University Evidence-based Practice Center under Contract No. 290-2007-10057-I). AHRQ Publication No. 10-E003. Rockville, MD: Agency for Healthcare Research and Quality. (When this happens, a C-section is done right away.)
  • The added risk that the baby will die from a problem with the scar during a VBAC labor compared with a repeat cesarean is very low. A baby will die due to uterine rupture about once in 5,200 labors after C-section.Guise, J.M., Eden, K., Emeis, C., . . . McDonagh, M. (2010). Vaginal birth after cesarean: New insights. Evidence Report/Technology Assessment No.191. (Prepared by the Oregon Health & Science University Evidence-based Practice Center under Contract No. 290-2007-10057-I). AHRQ Publication No. 10-E003. Rockville, MD: Agency for Healthcare Research and Quality.
  • If the scar gives way, some women require an urgent hysterectomy (removal of the uterus). However, C-sections also increase risk for urgent hysterectomy, and women who plan a VBAC are not more likely to experience an unplanned hysterectomy than women who plan a repeat C-section.Guise, J.M., Eden, K., Emeis, C., . . . McDonagh, M. (2010). Vaginal birth after cesarean: New insights. Evidence Report/Technology Assessment No.191. (Prepared by the Oregon Health & Science University Evidence-based Practice Center under Contract No. 290-2007-10057-I). AHRQ Publication No. 10-E003. Rockville, MD: Agency for Healthcare Research and Quality.

The following factors do not increase risk of the scar giving way during labor (we talk more about these factors here):

  • Unknown type of uterine scar
  • A low up-and-down (vertical) cut in the uterus was used for the previous C-section
  • The baby might be quite large (weigh more than 8 pounds, 13 ounces)
  • Pregnancy goes past 40 weeks, and labor is not inducedGuise, J.M., Eden, K., Emeis, C., . . . McDonagh, M. (2010). Vaginal birth after cesarean: New insights. Evidence Report/Technology Assessment No.191. (Prepared by the Oregon Health & Science University Evidence-based Practice Center under Contract No. 290-2007-10057-I). AHRQ Publication No. 10-E003. Rockville, MD: Agency for Healthcare Research and Quality.