The VBAC Pendulum

First "the studies" say "do this", then a few years later, more studies emerge to say "no wait a minute, what we told you first was wrong, now do the opposite". It happened with hormone replacement, and now it's happened with VBACs (Vaginal Birth After Cesarean). If the back-and-forth on medical advice makes you dizzy, you're not alone.

Quick Stats on VBACs and Cesarean Sections

• The rate of cesarean deliveries in 1937 was 3%

• The current rate of cesarean delivery is 31%

• VBAC's started to be widely offered in the 1980's

• 60 to 80 % of women who attempt a VBAC will have a healthy vaginal birth and a healthy baby.The VBAC rate* in 1980 was 3%

• VBACs peaked at 28% in 1996 and has steadily fallen since

• The current VBAC rate (as of 2005) is 8-10%

*VBAC rate = rate of vaginal births per 100 births to women with a previous cesarean delivery

Quick History of VBACs

Prior to the 1980's the "once a cesarean, always a cesarean" dominated the philosophy regarding women who'd had a prior cesarean birth. This idea was initially promulgated by EB Cragin in 1916. (they did c-sections in 1916?)

In 1937 the maternal mortality rate from cesarean section was 6%. Now, thanks to antibiotics, modern surgical techniques, and other advances, the risk of minor complications (such as infection, bleeding) is 1% and the mortality rate is 6/100,000 (although low, this is still three times the mortality rate for vaginal birth).

From the New England Journal of Medicine (Ecker and Frigoletto, March 1, 2007,  356(9):885.)

The Rise and Fall of VBAC's

Several studies conducted in the 1980's and 1990's revealed 60 to 80% of women who underwent a trial of labor had a successful VBAC. As more information was disseminated on the success of VBAC's, increasing VBAC was seen as one way of reducing the cesarean section rate. Some insurance companies and HMO's even went so far as to refuse to pay for elective repeat cesarean and required women to attempt VBAC's, whether they wanted to or not.

So if 60 to 80 % of women who attempt VBAC's succeed, why are fewer VBAC's being done?

A 1994 study published in the New England Journal of Medicine (NEJM) began to turn the tide on VBAC's. It showed infants of mothers attempting VBAC had a nearly three-fold (2.7x) rate of stillbirth, neonatal death, and other perinatal complications, compared with infants of mothers who had elective repeat cesarean sections.

The real clincher on VBAC's came with a 2001 study published in NEJM. This study showed women attempting VBAC had a five-fold risk of uterine rupture compared to women having a repeat elective c-section. Of women who had successful VBAC's, they had a higher risk of complications (postpartum hemorrhage, anemia, infection, bladder injury, hysterectomy, death of infant). This study also revealed women attempting VBAC, whose labor was induced or augmented with oxytocin or prostaglandins, had a much higher risk of uterine rupture than women who labored spontaneously.

Along with the new data emerging on the safety of VBAC's during the mid-1990'2 and early 00's, came an increase in multi-million dollar awards by juries to plaintiffs for VBAC's gone awry. People rarely sue for not doing a vaginal birth, but they frequently sue for not doing a cesarean section.

VBAC's gone awry quickly rose to the top of losses sustained by medical malpractice insurance companies in many states. The American College of Obstetrics and Gynecology stated in its 2004 summary of VBAC safety that it should only be attempted if a surgeon who can perform a cesarean section is "immediately available" (i.e. on the labor and delivery ward) during the entire labor, and if the hospital can provide 24-7-365 in-house anesthesia and surgical staff.

Many medical malpractice companies refused to insure doctors for doing VBAC's unless the ACOG criteria could be met. Smaller metropolitan community hospitals and rural hospitals do not have the resources to employ people to staff operating rooms 24-7-365 waiting for the next VBAC to come in. Reimbursement for VBAC is in many cases no different than reimbursement for normal vaginal birth despite the increased risk and staffing requirements entailed by VBAC.

In all practicality VBAC can only be performed at large major metropolitan hospitals which have full-time in-house obstetricians, anesthesiologists, and surgical technicians. This usually means a large university or teaching hospital.

Safety concerns, the malpractice liability, and staffing issues have combined to put the brakes on VBAC's.

Want to reduce your risk of having a cesarean section? See the upcoming post, "Increasing your odds of successful vaginal birth".

The issues and more are discussed in detail in the book, DIY Baby! Get yours now!