Birth Action Coalition Our Bodies, Our Babies, Our Births

VBAC is a safe option for many women. The main concern with VBAC is uterine rupture. The risk of uterine rupture, which depends upon the population studied and induction methods used, varies between 1/200 and 1/4151. Among thirty studies comprising 56,300 VBACs, the rate of stillbirths and newborn deaths attributable to uterine rupture was 1 in 3,3002. In another study3, of 4516 women attempting VBAC, there was 1 perinatal death. So the statistic depends on the population studied, but the risk of fetal death due to uterine rupture from a VBAC attempt is on the order of 1/3300. VBACs aside, according to the Center for Disease Control, in 1998 the fetal death rate in the US was 6.7 per 1006.7 live births plus fetal deaths4. In other words, a fetus is approximately 20 times more likely to die from causes other than uterine rupture.

Even in the absence of VBACs uterine ruptures can still happen. In a study conducted in California5 "only 34% of uterine ruptures were attributable to labor." In other words, 66% of the women experiencing a uterine rupture after having had a prior cesarean were not in labor when the rupture happened. So, elective repeat cesarean delivery did not prevent the ruptures. Since elective repeat cesarean doesn’t necessarily prevent uterine rupture in the majority of cases, it is very important for hospitals to work to decrease the primary cesarean rate.

The safest mode of delivery varies from woman to woman and pregnancy to pregnancy. According to a 2006 study published by the American College of Obstetricians and Gynecologists6, "a trial of labor after cesarean seems to be as safe for the mother and infant as planned cesarean delivery, and the hospital stay is shorter." That is why women should be allowed to make this choice for themselves with their care provider.

According to ‘A Guide to Effective Care in Pregnancy and Childbirth’7, a text for obstetricians and midwives in the UK which is the ‘gold standard’ of evidence-based care:

"Overall, attempted vaginal birth for women with a single previous low transverse cesarean section is associated with a lower risk of complications for both mother and baby than routine repeat cesarean section."

"The morbidity (illness) associated with successful vaginal birth is about one-fifth that of elective cesarean. Failed trials of labour, with subsequent cesarean section, involve almost twice the morbidity of elective section, but the lower morbidity in the 80% of women who successfully give birth vaginally means that overall women who opt for a planned vaginal birth after cesarean suffer only half the morbidity of women who undergo an elective section."

According to a representative from Cottage Hospital, the hospital "is ready to perform emergency cesareans 24x7" and "Cottage has the ability to mobilize and act quickly when needed." If this is the case, then the reason the hospital originally gave for the ban (not enough staff to support VBAC) does not make sense. If we use the uterine rupture rate of 1/200, and the previous figure that 4% of births at Cottage were VBACs before the ban, Cottage would still only expect to see a uterine rupture due to VBAC every 2-3 years and a fetal death due to VBAC every 10 or so. This is certainly less risky than many of the other births that take place at Cottage due to other complications.

In 2005 The American Academy of Family Physicians Commission on Clinical Policies and Research convened a panel to systematically review the available evidence on trial of labor after cesarean delivery (TOLAC) using the Agency for Healthcare Research and Quality Evidence Report on Vaginal Birth After Cesarean (VBAC).8 Their recommendations include the following:

• Women with one previous cesarean delivery with a low transverse incision are candidates for and should be offered a trial of labor (TOL)

• TOLAC should not be restricted only to facilities with available surgical teams present throughout labor since there is no evidence that these additional resources result in improved outcomes.

• At the same time, it is clinically appropriate that a management plan for uterine rupture and other potential emergencies requiring rapid cesarean section should be documented for each woman undergoing TOLAC.

They also state that,

"Some have questioned the assumptions that seem to underpin the immediately available policy. For example, the policy assumes that having a surgical team immediately available will reduce morbidity or mortality from uterine rupture. The AAFP TOLAC Panel felt this was a debatable assumption. Similarly, the ACOG policy suggests that one rare obstetrical catastrophe (e.g., uterine rupture) merits a level of resource that has not been recommended for other rare obstetrical catastrophes (e.g., shoulder dystocia, abruptio placenta, cord prolapse) that may actually be more common. However, it may be argued that, while these other catastrophes are largely not predictable, permitting a TOL in a mother with a previous cesarean is a planned event that may demand a different degree of preparedness.
While adverse consequences of a TOLAC are distinctly uncommon and must be balanced against attendant risks associated with ERCD, current risk management policies across the United States restricting a TOL after previous cesarean section appear to be based on malpractice concerns rather than on available statistical and scientific evidence. The TOLAC Panel found no systematic evidence suggesting that improved outcomes for TOLAC patients resulted from restricting a woman’s ability to undergo a TOLAC based on the availability of resources not usually present for other women in labor, the institutional setting, or the timeliness of operative delivery."

According to an August 31, 20069 news release, "Researchers emphasized that cesarean delivery is major abdominal surgery and that expectant women and physicians should carefully consider cesarean-related surgical complications and the increased risk of death when choosing the method of delivery." Cesarean section is not necessarily safer for mother or baby and carries many risks including two to four times a greater chance of maternal death, as well as increased risk of emergency hysterectomy, injury to blood vessels and other organs, chronic pain due to internal scar tissue, increased chance of re-hospitalization and complications involving the placenta in subsequent pregnancies, and risks to the infant including an increased risk of respiratory distress syndrome, prematurity, and the development of childhood asthma and allergies10. The recovery from a cesarean is much longer than for a vaginal birth, involving more pain, more difficulty establishing breastfeeding, and a longer hospital stay. They are important facts for women to be aware of when agreeing to a cesarean.

1. 1. Katharina E. Kieser, MD and Thomas F. Baskett, MB (2002) A 10-Year Population-Based Study of Uterine Rupture, Obstetrics and Gynecology 2002;100:749-753
2. 2. Henci Goer, BA, LCCE (2002) VBAC and the New England Journal of Medicine Birth 29 (2) , 150–151 doi:10.1046/j.1523-536X.2002.01782.x
3. 3. Katharina E. Kieser, MD and Thomas F. Baskett, MB (2002) A 10-Year Population-Based Study of Uterine Rupture, Obstetrics and Gynecology 2002;100:749-753
4. 4. www.cdc.gov/nchs/about/major/fetaldth/abfetal.htm
5. 5. Lisa M. Korst, Kimberly D. Gregory et al., Vaginal Birth After Cesarean and Uterine Rupture Rates in California, Obstetrics and Gynecology 1999;94:985-989
6. 6. Ron Gonen, Victoria Nisenblat (2006) Results of a Well-Defined Protocol for a Trial of Labor After Prior Cesarean Delivery, Obstetrics and Gynecology 2006;107:240-245
7. 7. M. Enkin, M.J.N.C. Keirse, J. Nielson, C. Crowther, L. Duley, E. Hodnett, and J. Hofmeyr, A Guide to Effective Care in Pregnancy and Childbirth. Oxford University Press, 2000.: http://www.vbac.com/chapter38.html
8. 8. www.aafp.org/PreBuilt/clinicalrec_tolac.pdf
9. 9. www.acog.org/from_home/publications/press_releases/nr08-31-06-2.cfm
10. 10. M. Salam, H. Margolis, R. McConnell, J. McGregor, E. Avol , F. Gilliland (2006) Mode of Delivery Is Associated With Asthma and Allergy Occurrences in Children, Annals of Epidemiology, Volume 16, Issue 5, Pages 341 - 346