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Will a VBAC affect your postpartum recovery?
If you have a vaginal birth, the days and weeks after the birth are likely to be much easier because you won’t be recovering from major surgery. This will be even more important than it was the first time because you already have another child or children at home. A VBAC that ends in a repeat cesarean can be disappointing, but even so, most women are glad they tried.
When would VBAC be inadvisable?
Doctors agree that planned cesarean is preferred when the mother has a vertical (also called “classical”), T-shaped, or J-shaped uterine incision. However, in most countries, the low transverse incision has been the norm for many years. Reasons for a vertical incision include the placenta is overlaying the cervix (placenta previa), some breech presentations (the baby is buttocks, knees, or feet down), and some emergency cesareans.
What are the potential risks of VBAC?
Symptomatic scar separation: The main fear with labor after a cesarean is that the scar will open enough to cause bleeding or for the umbilical cord or the baby to pass through the opening. Among thirty studies totaling 56,300 VBACs, the rate of symptomatic scar separation was 4 per 1,000 (15,30). Even so, few instances where this occurs result in harm to the baby, which is the real issue. The perinatal mortality rate (stillbirths and newborn deaths together) from this cause was 3 per 10,000. This did not differ from the perinatal mortality rate of 2 per 10,000 in 29,900 planned cesareans. Nor does planning a cesarean eliminate the risk of the scar giving way. Several large studies reported scar separation rates ranging from 2 to 3 per 1,000 with repeat cesarean, not much less than the 4 to 6 per 1,000 reported in VBAC labors (17,21,30).
More likelihood of complications if the labor ends in a cesarean: You are somewhat more likely to have complications such as infection with a cesarean after labor compared with a planned cesarean. Nonetheless, planned cesareans have substantially higher complication rates than vaginal births, and most properly managed labors after a cesarean should end in vaginal birth.
In summary, VBAC introduces a slightly greater risk of serious complications relating to the scar, but this is more than counterbalanced by a host of complications that occur more frequently with cesarean section.
What is a reasonable VBAC rate?
Among 34 studies of labor after a prior cesarean, totaling 38, 700 women, all but one reported VBAC rates above 60 percent (15). Half reported rates between 70 and 79 percent. An analysis of 17,600 labors after cesarean in Switzerland reported a 75 percent rate (30). Therefore, with a midwife or doctor committed to VBAC, your overall odds of VBAC should be three out of four, and you would be well advised to seek another practitioner if yours has a rate less than 70 percent.
The odds of VBAC also shift up or down depending on various factors. As you would expect, you are more likely to have a vaginal birth than the overall average if you have had a prior vaginal birth, less likely if your prior cesarean was for poor progress or this baby is big. You are also less likely to have a vaginal birth if you are induced. Nonetheless, the VBAC rates still fall around 66 percent, or two out of three with supportive caregivers (3,9,26,30).