Attempting vaginal birth after cesarean is appropriate for the majority of women who have had a prior cesarean and for many women who have had two prior cesareans, according to new guidelines from the American College of Obstetricians and Gynecologists.
While many physicians have long believed “once a cesarean, always cesarean,” this attitude began to change in the 1970s. At that time, evidence started to accumulate supporting trial of labor after previous cesarean delivery (TOLAC) and vaginal birth after cesarean delivery (VBAC).
The VBAC rate increased from 5% in 1985 to 28% in 1996, but then fell to 8.5% in 2006. According to a 2010 National Institutes of Health Consensus Development Conference quoted in the new guidelines, the lowered rate reflects restrictions by hospitals and insurers as well as concerns by physicians on the risks and benefits of TOLAC and VBAC
The new guidelines replace a practice bulletin issued in July 2004 and a committee opinion issued in August 2006. The guideline's recommendations are divided into three levels depending on the strength of the scientific evidence (Obstet. Gynecol. 2010;116:450-63). The three level A recommendations are the strongest as they are based on “good and consistent scientific evidence.” They are as follows:
▸ Most women with one previous cesarean delivery with a low-transverse incision are candidates for and should be counseled about VBAC and offered TOLAC.
▸ Epidural analgesia for labor may be used as part of TOLAC.
▸ Misoprostol should not be used for cervical ripening or labor induction in patients who have had a cesarean delivery or major uterine surgery.
Among the six level B recommendations, based on “limited or inconsistent scientific evidence” are the following:
▸ Women with two previous low-transverse cesarean deliveries may be considered candidates for TOLAC.
▸ Those at high risk for complications (such as women with previous classical or T-incision or prior uterine rupture) and those in whom vaginal delivery is otherwise contraindicated (such as women with placenta previa) are generally not good candidates for planned TOLAC.
▸ Induction of labor for maternal or fetal indications remains an option in women undergoing TOLAC.
▸ TOLAC is not contraindicated for women with previous cesarean delivery with an unknown uterine scar type unless there is a high clinical suspicion of a previous classical uterine incision.
▸ Women with one previous cesarean delivery with a low transverse incision, who are otherwise appropriate candidates for twin vaginal delivery, may be considered candidates for TOLAC.
ACOG also made two level C recommendations, which are based primarily on “consensus and expert opinion.” They are as follows:
▸ Because of the unpredictable risks of uterine rupture and other complications, TOLAC should be undertaken only at facilities capable of emergency deliveries.
▸ The ultimate decision on TOLAC and VBAC rests with the patient after consultation with her health care provider. The provider should discuss the potential risks and benefits of both TOLAC and elective repeat cesarean delivery.
Repeat cesarean deliveries and TOLAC both carry risks of maternal hemorrhage, infection, operative injury, blood clots, hysterectomy, and death. But a successful VBAC has a lower risk of complications than an elective cesarean delivery.
Risk of uterine rupture during a TOLAC is low (0.5%-0.9%), but if it occurs, it is an emergency situation. Thus, a TOLAC is most safely undertaken where staff can immediately provide an emergency cesarean, as reflected in the above guidelines.
“Given the onerous medical liability climate for ob.gyns., interpretation of the College's earlier guidelines led many hospitals to refuse allowing VBACs altogether,” ACOG president Richard N. Waldman said in the prepared statement.
Dr. Jeffrey L. Ecker of Massachusetts General Hospital, Boston, said in the statement, “In making plans for delivery, physicians and patients should consider a woman's chance of a successful VBAC as well as the risk of complications from a trial of labor, all viewed in the context of her future reproductive plans.” As the immediate past vice chair of ACOG's Committee on Practice Bulletins-Obstetrics, Dr. Ecker co-wrote the new practice guidelines with Dr. William A. Grobman of Northwestern University, Chicago.
According to the Centers for Disease Control and Prevention, the rate of cesarean deliveries in the U.S. in 2008 was 32.3%, the highest ever recorded and the 12th consecutive year of increase.
“The current cesarean rate is undeniably high and absolutely concerns us as ob.gyns.,” said Dr. Waldman, chair of the ob.gyn. department at St. Joseph's Hospital Health Center in Syracuse, N.Y. “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.”
Disclosures: None was reported.
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