Attitudes and practices abut Vaginal Birth After Cesarean (VBAC) have been changing since 1916, when it was declared “Once a Cesarean, always a Cesarean”. In the last 20 years, attitudes and practices have been especially pendulous, with countless studies being conducted and The American College of Obstetrics and Gynecology (ACOG) recommendations regarding VBAC changing several times. Each of these changes have has a dramatic effect on the kind of care women and their babies have access to.
In the 1990’s, there was enough evidence to support a trial of labor for women who had a previous cesarean, creating a new trend in practice. In “Trends in cesarean birth and vaginal birth after previous cesarean, 1991-99”, authors Menacker and Curtin report on these trends. They found that the US VBAC rate increased by 33% between 1991 and 1996 and fell 17% between 1996 and 1999 for all age and ethnic groups ( Menacker and Curtin 1). These dramatic differences in rate are due to ACOG recommendations, which were mostly in favor of VBAC.
In 1999 the ACOG revised their position on VBAC, making it stricter and subsequently ending the trend in practice. Their reasoning for the new guideline was, "Because uterine rupture may be catastrophic”, institutions needed to be “equipped to respond to emergencies with physicians immediacy available to provide emergency care” (Win 1). ACOG was unable to provide any scientific evidence to support this, however. Instead they were only able to offer medical-legal reasons, stating “...Increasingly, these adverse events during trial of labor have led to malpractice suits” (Wagner 1). This affected many rural communities which could not offer 24 hour emergency care, which subsequently contributed to an increase in the overall c-section rate and decreased the number of women “allowed” to have a trial of labor.
By 2002, a mere 3 years after the new guideline had been created, the VBAC rate had dropped 12%, with no improvement or change in neonatal or maternal mortality rates (Win 1). Hundreds of hospitals across the US had either completely banned or had a de facto ban in place prohibiting women from having a trial of labor after a previous Cesarean, further driving the Cesarean rate up and the VBAC rate down.
In a 1999 article called “VBAC: Protecting patients, defending doctors” authors Deutchman and Roberts reflect on the complexity of the new, more restrictive guidelines, stating that “The irony of the ACOG recommendation is that it may result in what it seeks to avoid: worse pregnancy outcomes and increased litigation risk. As more maternity services are discontinued and women must leave their communities for pregnancy care, mortality and morbidity rates increase for both mothers and infants” and concludes that,
“Large population-based studies have shown no difference in maternal mortality between the two delivery approaches. Compared with trial of labor, elective repeat cesarean birth is associated with a 2 percent greater risk of maternal infection and a 1 percent greater risk of maternal hemorrhage requiring transfusion. Uterine rupture occurs 0.24 to 0.77 percent more frequently with trial of labor than with repeat cesarean birth, and perinatal death occurs 0.10 to 0.40 percent more frequently” (Deutchman and Roberts).
Since the new 1999 ACOG guideline revision, the body of evidence in favor of VBAC has grown. In the article “Stricter VBAC Guidelines Does Not Affect Mortality”, Kenneth W. Win states, “Maternal death rates did not change significantly after the guideline revision, regardless of delivery type...pregnant women who have had a previous cesarean delivery (should) be informed about these encouraging findings in addition to the risks associated with VBAC” (Win 1). A retrospective cohort study called “A new perspective on VBAC: A retrospective cohort study” was
“undertaken comprising a consecutive cohort of 21,389 women who delivered, stratified by Robson's criteria into Robson groups 1-5. Those in Robson groups 6-10 were not included. Demographic data and maternal/neonatal outcomes were reviewed, with main outcome measures comprising uterine rupture, post-partum haemorrhage (PPH), 3rd/4th degree tears and neonatal morbidity” Authors Rozen, Ugoni and Sheehan found that for women who had a vaginal birth after a prior cesarean, there was no increase in postpartum hemorrhage, vaginal tears, or neonatal complications and concluded.The maternal and neonatal morbidity associated with VBAC is comparable to primiparous women undergoing a vaginal birth” (Rozen, Ugoni and Sheehan 1).
Despite mounting evidence in favor of VBAC, guidelines did not change. By 2007, the c-section rate had climbed to 31.8% of all births in the US.
In 2010, as a response to this record high c-section rate and to the growing body of research in favor of Vaginal Birth After Cesarean, both the National Institute of Health (NIH) and American College of Obstetrics and Gynecology reviewed and revised their statements regarding VBAC. In a 2010 article called, “NIH Consensus Development Conference on Vaginal Birth After Cesarean: New Insights” 21 experts in pertinent fields presented new data to a panel and audience. The conclusion of the data presented was as follows,
“Given the available evidence, trial of labor is a reasonable option for many pregnant women with one prior low transverse uterine incision. The data reviewed in this report show that both trial of labor and elective repeat cesarean delivery for a pregnant woman with one prior transverse uterine incision have important risks and benefits and that these risks and benefits differ for the woman and her fetus” (NIH 1)
Finally, in July of 2010, the ACOG revised their guideline regarding vaginal birth after cesarean-
“Attempting a vaginal birth after cesarean (VBAC) is a safe and appropriate choice for most women who have had a prior cesarean delivery, including for some women who have had two previous cesareans...the current cesarean rate is undeniably high and absolutely concerns us as ob-gyns..these VBAC guidelines emphasize the need for thorough counseling of benefits and risks, shared patient-doctor decision making, and the importance of patient autonomy. Moving forward, we need to work collaboratively with our patients and our colleagues, hospitals, and insurers to swing the pendulum back to fewer cesareans and a more reasonable VBAC rate.” (ACOG 1)
References
Kenneth W Lin. (2006). Stricter VBAC Guideline Does Not Affect Mortality. American Family Physician, 74(8), 1411-1412.
Curtin SC., , and Menacker . "Trends in cesarean birth and vaginal birth after previous cesarean, 1991-99.." National Vital Statstics Report . 1.16 (2001): Print.
Mark Deutchman, & Richard G Roberts. (2003). VBAC: Protecting patients, defending doctors. American Family Physician, 67(5), 931-2, 935-6.
Rozen, , Sheehan, and Ugoni. "A new perspective on VBAC: A retrospective cohort study.." Women birth- Department of Obstetrics and Gynaecology. 1. (2010): Print.
National Institute of Health, "NIH Consensus Development Conference on Vaginal Birth After Cesarean: New Insights." Obstetrics & Gynecology. 115.6 (2010): Print.
Wagner, Marsden. "What Every Midwife Should Know About ACOG and VBAC: Critique of ACOG Practice Bulletin No. 5, July 1999, “Vaginal Birth After Previous Cesarean Section." Midwifery Today. (1999): Print.
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