VBAC

Question 1

Methods of delivery ordered by risk

Answer 1

VBAC < ERCD < failed TOLAC

Question 2

What is the vaginal delivery rate in women undergoing a TOLAC

Answer 2

60-80%

Question 3

Increased probability of VBAC success

Answer 3

• prior vaginal birth

- spontaneous labor

Question 4

Decreased probability of success

Answer 4

• recurrent indication for initial C-section (labor dystocia)
• increased maternal age
• non-white ethnicity
• gestational age >40 wks
• maternal obesity
• preeclampsia
• short interpregnancy interval
• increased neonatal birth weight

Question 5

Who are candidates for a trial of labor after previous cesarean delivery?

Answer 5

• Typically, > or equal to 60-70% chance of success is used since this represents the point at where the risk of failure is equal to that of the risk of an elective repeat cesarean
• Most women with one previous cesarean delivery with a low transverse incision are potential candidates for VBAC.

Question 6

Are women with greater than two prior C-sections candidates for TOLAC?

Answer 6

Data is limited; in women with two prior C sections, it is reasonable to counsel for TOLAC

• One study showed no increase in risk, another showed a doubling in risk.
• Both studies showed an increase in morbidity

Question 7

Are women with macrosomic fetuses candidates for TOLAC?

Answer 7

• Fetus 4000g-4500g
• Prior hx of C section for dystocia, less likely to be successful
• Possible increased risk of uterine rupture in patients with no prior vaginal delivery and a macrosomic infant.
• Suspected macrosomia alone should not prevent a patient from TOLAC

Question 8

Are women >40 wks GA candidates for TOLAC?

Answer 8

• Lower chance of success, but shouldn’t preclude attempt.

Question 9

Are women with a low vertical incision candidates for TOLAC?

Answer 9

• Show no difference in risk of uterine rupture.

- Unclear

Question 10

Are women with an unknown type of previous uterine incision candidates for TOLAC?

Answer 10

Yes, unless clinical suspicion for classical scar is high

Question 11

Are women with twin gestation candidates for TOLAC?

Answer 11

Yes, no additional risk