Ten Thoughts on VBAC
There has been some discussion recently in the blogs and the twitterverse about VBAC. Some have expressed a concern that not enough women are being offered VBAC, and that not enough doctors are supportive of it when the facilities are available. I have a few thoughts on this.
VBAC, or Vaginal Birth after Cesarean, is something that gets a lot of discussion, because any discussion about VBAC is basically a discussion an inverse interplay between fetal and maternal well being.
The underlying fetal concern is that in very rare cases, the previous uterine scar can rupture in labor, which can result in fetal injury or death. Most large series demonstrate a risk if about 0.5% in natural labor, and about 1% in pitocin augmented labor, assuming that the woman has had a single low transverse hysterotomy (cesarean scar.) These risks increase for low vertical hysterotomies (1-3%) and even further for high vertical (classical) scars. Some large series have shown slightly lower or higher rupture rates. In cases of uterine rupture that happen in hospital, most patients can successfully have a emergent cesarean delivery and deliver an uninjured baby, but in some cases (10-20%) there will be fetal injury or death. This risk can be eliminated by choosing to do repeat cesarean deliveries prior to labor.
But there is another side to this coin. Choosing repeat cesarean is less risky for the infant, but now exposes the mother to surgical risk and recovery issues that would be avoided with a successful VBAC. While generally safe in any one case, in aggregate cesarean delivery exposes the mother to small but real risks of significant complications. Minor risks include wound infection or separation, while more major risks include severe bleeding requiring transfusion, hysterectomy, or even death. These major risks are very rare, but when looking at thousands of cases we will see them. Furthermore, any woman who has a repeat cesarean delivery has a longer recovery course and more pain than a woman who is able to successfully have a VBAC, and may have other problems such as breastfeeding difficulty.
So here are a few of my thoughts on this issue:
1) VBACs are unquestionably higher risk than routine vaginal deliveries. Though the risk of uterine rupture is small, it is real, and should not be ignored. ACOG recommends that VBACs occur in hospital where there is in house anesthesia and obstetrics and the ability to emergently perform a cesarean delivery. This is a wise recommendation, and should be followed. Uterine rupture can be managed by an efficient and skilled team, but if things are not handled quickly and correctly it can result in severe fetal injury or death. We should not forget that.
2) VBAC should not happen at home. I have recently referred to that as a game of Russian Roulette, and defend that view here. In this case the gun has 100 barrels, but the bullet will kill the baby just the same. If a woman can honestly say they are willing to take a 0.5% to 1% risk of disaster, then fine, but to me that risk is way too high. I think home birth is an acceptable option in many cases, but VBAC is not one of them.
3) VBAC should be encouraged when the facilities are available. It is a shame when doctors who work in facilities that have the ability to provide VBAC services aren’t willing to do this. It is also a shame if doctors overemphasize the fetal risks of VBAC, which are minimal if properly managed.
4) Those that fight for VBAC rights need to understand that physicians are under great pressure from malpractice carriers, and in some cases hospitals, to not provide VBAC. Malpractice carriers in some cases will not allow their covered physicians to VBAC, as uterine ruptures are unpredictable and carry a high risk of litigation if they occur, despite thorough informed consent prior to the VBAC attempt. Hospitals also accept liability by providing VBAC services, which amounts to financial payout, without getting much in return. When they provide VBAC services they do so in order to provide more comprehensive care, but do so at some liability risk. It is important to understand that given legal liability, doctors and hospitals are encouraged to take predictable risks (cesarean complications) over unpredictable risks (uterine ruptures.) Legal protection for physicians and hospitals who have predictable VBAC complications would go a long way to increasing VBAC availability.
5) Physicians also must stay in or near the hospital when a VBAC attempt is going on, which can be logistically difficult. Obviously midwives don’t have this problem, but midwives also can’t do the emergent cesarean delivery if it were needed. The reality is that for a small private practice physician to stay in house for an entire VBAC labor likely costs that physician several thousand dollars in income, and all the while his or her office overhead continues to accrue. This is avoided in large groups that have a permanent in house covering physician or academic practices, but in small practices this can make VBAC very difficult to work into a practice.
6) The choice whether or not to VBAC has a lot of things that goes into it. The number of children a woman wants to have is a big issue. If a woman plans only 1 more child after her first cesarean, the absolute risk to that woman is very low with her first repeat. Risks start to rise substantially as she has more repeat cesareans, so a woman who plans 5-6 children gets a relatively greater benefit from the first successful VBACs (and presumably subsequent VBACs) than the woman who has only 1 VBAC. A woman who wants to be sterilized is sometimes encouraged to have a repeat cesarean and sterilization at one time, but I would not recommend this. Hysteroscopic sterilization can be done after a successful VBAC at 10x less risk than an open procedure (though risks for either are very low.).
7) VBAC success rates are difficult to predict, and vary greatly on the provider who is deciding when to quit and do a cesarean. There are many models for calculating success rates out there, but are difficult to extrapolate to different providers. Women who had a cesarean for breech tend to have the highest VBAC rates, then women with cesarean for fetal distress, then women for cesarean for arrested labor. Importantly, even the lowest success rate groups have a 60-65% or greater chance of successful VBAC in most series, which is not substantially higher than underlying cesarean rates. There is very little evidence that we can predict VBAC failure reliably in any woman, and substantial evidence that the majority of women can successfully VBAC.
8 ) It is unlikely that rural (and some semi-rural) areas will have VBAC access, due to the infrastructure that is required to provide it. We can lament this all we want, but this is a reality that is unlikely to change.
9) Given the current medicolegal climate, some women may need to travel some to do a VBAC in a hospital that has the infrastructure to provide it. Having a VBAC in a hospital not equipped to handle a uterine rupture quickly and efficiently is a bad idea.
10) The single most important thing we can do to deal with VBAC issues is to not have them at all, by avoiding the first cesarean section. Many cesareans are absolutely necessary, but when possible we should achieve vaginal deliveries. I’m willing to push some grey cases that others might deliver by cesarean. Sometimes that means being more patient with a slow labor. Sometimes that means operative vaginal delivery. Because of that, more of my patients will have easy multiparous second labors rather than having to worry about VBAC issues. There is a receiver operator curve for cesarean necessity. Most OBs should push their needle a little towards “specificity”.