Many women who have given birth by cesarean section (also called a C-section) would like to know if they can deliver their next baby vaginally. For a long time physicians followed the guideline: “once a C-section, always a C-section.” This meant that many women who wanted to experience a vaginal birth were told that they could not. Physicians worried that women who had had a C-section might be at risk for their uterus (womb) tearing along the previous surgical incision when they were in labor again. If this happened during labor it could put both the mother and baby at risk for serious harm and require an emergency C-section. However in the 1970s, doctors and a group of women who had given birth by C-section conducted research to test this theory. They pioneered doing a trial of labor to deliver vaginally. This research and newer studies shows that a trial of labor in women who had a previous C-section is safer than we used to think. The risk of the uterus tearing along the old incision is about 0.1 to 1.5 percent, which is about the same, or lower, than many other commonly accepted risks in obstetrics. For these reasons the National Institutes of Health (NIH) and the American Congress of Obstetricians and Gynecologist (ACOG) say that having a trial of labor to have a vaginal birth is a reasonable option for most women who have had a prior C-section.
Overall about 60-80 percent of women with a prior C-section who attempt a trial of labor successfully deliver vaginally. There are many factors that influence the likelihood of a vaginal delivery. Women who go into labor naturally or have given birth vaginally previously are more likely to deliver vaginally. Conversely, there are several factors that decrease the probability of success:
- Pregnancy lasting past the due date (gestational age greater than 40 weeks)
- Older age of the mother
- Larger birth weight of the baby
- Obesity in the mother
- Nonwhite ethnicity
- Short spacing of pregnancies
There are several reasons why women may wish to attempt a vaginal birth, especially if they plan on having several more children. Though surgical techniques have greatly increased the safety of C-sections, it is still a major surgery with potential complications including increased risk of bleeding, more pain after delivery, and longer hospital stays, not to mention increased cost. For women planning on having several children in the future, repeated C-sections leave scars on the uterus that could potentially interfere with how the placenta attaches to their uterus in later pregnancies. This could make later pregnancies more complicated.
If you had a C-section with your last pregnancy, do not assume you will need one with your next baby. To make the best decision, please discuss the different options including the risks and benefits with your OB provider.
Dr. Sundin practices Family Medicine with Obstetrics at Valley Medical Center’s Highlands Clinic in Renton, WA. He can be reached at 425.656.5500.