VBAC (Vaginal Birth After Cesarean Section)

by Regula Elisabeth Burki, MD, FACOG

Partially under the pressure of lawsuits, the cesarean section rate increased from 5% in 1970 to 25% in 1988. Doctors are rarely sued for a poor outcome if they have performed a cesarean section but they are almost always sued when they have not. The courts firmly believed for many years that electronic fetal monitoring could identify practically every baby in trouble and that failure to recognize an abnormal tracing and immediately perform a cesarean section constituted "malpractice" and grounds for several million dollars in payment.

Doctors started practicing what is referred to as "defensive medicine" under the rule "when in doubt, section." Women paid with a high rate of often unnecessary cesarean sections. More recent research has shown that fetal monitor tracings are not as failsafe as previously thought and that many serious fetal problems start long before the onset of labor. The practice of "once a cesarean, always a cesarean," which dominated American obstetrics for nearly 70 years, further contributed to the high cesarean delivery rate, as did the fact that more older women with more medical problems and less stretchy tissues began having babies.

In the 1980s, it became clear that sometimes a trial of labor (meaning attempting labor) after a previous cesarean delivery can be safe for carefully selected patients. The National Institute of Health and the American College of Obstetricians and Gynecologists began to encourage the practice for carefully selected women with a low transverse uterine incision. Obviously, when a tiny woman with a small pelvis is expecting another ten-pound baby, the baby will not fit the second time around either!

Unfortunately, many managed care plans proceeded to mandate that all women must have a trial of labor before the insurance company would pay for a cesarean section, and went on a publicity campaign denouncing doctors and hospitals with high cesarean delivery rates. As a result, in many lay circles a doctor's cesarean rate became the sole criteria of competence as an obstetrician!

After 20 years of experience with VBACs, the following points have been shown by several well conducted studies:

  • Major complications, such as uterine rupture, surgical complications, and need for hysterectomy, are almost twice as likely with an attempted VBAC as with a scheduled repeat cesarean section.
  • The risk of uterine rupture is almost five times higher when VBAC labor is induced with prostaglandins; when induced without prostaglandins the risk is not much higher than that of spontaneous labor.
  • Uterine rupture increases the risk of death for the baby ten-fold.
  • Depending on how carefully VBAC candidates are selected, in 20-40% of cases the trial of labor fails and the woman ends up with a cesarean section anyway.
  • There are no studies showing that VBAC or cesarean delivery is safer for the mother or the baby.
  • A successful VBAC has a lower risk of blood transfusion and infection, a shorter hospital stay and shorter postpartum recovery than a repeat cesarean section. It is also cheaper unless the labor was prolonged and complicated.
  • A failed VBAC followed by a cesarean section carries a much higher risk of major and minor complications and is more expensive than a scheduled repeat cesarean section.
  • The American College of Obstetricians and Gynecologists advises that most women with one or two low-transverse uterine incisions from a previous cesarean delivery who have no contraindications for vaginal birth are candidates for an attempted VBAC. The risk of uterine rupture increases with the number of previous uterine incisions. VBAC should be tried only if a physician capable of performing an emergency cesarean section is immediately available to monitor the entire active phase of labor. The mother should be in a hospital with an in-house anesthesiologist and operating room personnel.
  • No women should be bullied into a VBAC by her peers, her midwife, her doctor or her insurance plan.

Dr. BurkiDr. Regula E. Burki is an OB/GYN and a Fellow of the American College of Obstetricians and Gynecologists (ACOG). Prior to entering private practice she was a Clinical Fellow in Obstetrics and Gynecology at Harvard University and completed a residency in Obstetrics and Gynecology at Massachusetts General Hospital in Boston, where she served as chief resident. She maintains a practice to Bern, Switzerland. The views Dr. Burki expresses are her personal views and not necessarily those of ACOG. This article is xcerpted from her book Birthing.

All content copyrighted © Regula Burki. Permission to republish granted to Pregnancy.org, LLC.