ACOG Issues Less Restrictive Guidelines for Vaginal Birth After Cesarean Delivery

From Medscape Medical News

Laurie Barclay, MD

July 22, 2010 — Trial of labor after previous cesarean delivery (TOLAC) is safe and appropriate for most women with previous cesarean delivery, including some women with 2 previous cesarean deliveries, according to less restrictive guidelines issued by the American College of Obstetricians and Gynecologists (ACOG). The revised recommendations for planned vaginal birth after cesarean (VBAC) are reported in a practice bulletin published in the August issue of Obstetrics & Gynecology.

"The current cesarean rate is undeniably high and absolutely concerns us as ob-gyns," said ACOG president Richard N. Waldman, MD, in a news release. "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 defines the term trial of labor as a trial of labor in women who have had a previous cesarean delivery, regardless of outcome. Also, the term vaginal birth after cesarean delivery is used to denote a vaginal delivery after a trial of labor.

Benefits of VBAC

ACOG's guidelines indicate the potential advantages of VBAC for the individual patient. These benefits include maternal preference and reduced maternal morbidity and a lower risk for complications in future pregnancies. At the population level, VBAC is also associated with a lower overall rate of cesarean deliveries.

"Approximately 60–80% of appropriate candidates who attempt VBAC will be successful," said statement coauthor Jeffrey L. Ecker, MD, from Massachusetts General Hospital in Boston. "A VBAC avoids major abdominal surgery, lowers a woman's risk of hemorrhage and infection, and shortens postpartum recovery. It may also help women avoid the possible future risks of having multiple cesareans such as hysterectomy, bowel and bladder injury, transfusion, infection, and abnormal placenta conditions (placenta previa and placenta accreta)."

Because failed TOLAC is associated with increased maternal and perinatal morbidity vs elective repeat cesarean delivery, it is important to evaluate individual risks and the likelihood of VBAC when deciding whether TOLAC is a feasible option. A successful VBAC has fewer complications than an elective repeat cesarean delivery, and the new guidelines attempt to point out the risks and benefits of TOLAC in different clinical settings and to offer practical recommendations for treatment and counseling of women who will undergo VBAC.

"The College guidelines now clearly say that women with two previous low-transverse cesarean incisions, women carrying twins, and women with an unknown type of uterine scar are considered appropriate candidates for a TOLAC," Dr. Ecker said. "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."

ACOG's Revised VBAC Guidelines

The practice bulletin makes the following specific recommendations based on good, consistent scientific evidence (level A):

* TOLAC may be appropriate for most women with 1 previous cesarean delivery via a low transverse incision. These women should be counseled about VBAC and offered TOLAC as a delivery option.
* As part of TOLAC, epidural analgesia may be used for labor.
* For women who have undergone previous cesarean delivery or major uterine surgery, misoprostol should not be used for third-trimester cervical ripening or labor induction.

Also included in the statement are the following recommendations based on limited or inconsistent scientific evidence (level B):

* TOLAC may be considered in women with 2 previous low transverse cesarean deliveries.
* TOLAC may be considered in women with 1 previous cesarean delivery via a low transverse incision who are otherwise appropriate candidates for twin vaginal delivery.
* In women with previous cesarean delivery via low transverse uterine incision who are at low risk for adverse maternal or neonatal outcomes from external cephalic version and TOLAC, external cephalic version for breech presentation is not contraindicated.
* Planned TOLAC is generally not recommended in women at high risk for complications, such as those with classic or T-incision, prior uterine rupture, or extensive transfundal uterine surgery. Also, planned TOLAC is not recommended in women in whom vaginal delivery is contraindicated, such as those with placenta previa.
* In women undergoing TOLAC, it is permissible to induce labor, when appropriate, based on maternal or fetal indications.
* For women with previous cesarean delivery with an unknown uterine scar type, TOLAC is not contraindicated unless there is a high clinical suspicion for a previous classic uterine incision.

Finally, the statement also provides the following recommendations that are based mainly on consensus and expert opinion (level C):

* Women undergoing TOLAC should do so at facilities able to perform emergency deliveries and with staff immediately available to provide emergency care because of unpredictable risks associated with TOLAC.
* When these resources are not available, women should be clearly advised regarding greater risks for TOLAC and management alternatives, and counseling and the management plan should be documented in the medical record.

"It is absolutely critical that a woman and her physician discuss VBAC early in the prenatal care period so that logistical plans can be made well in advance," said coauthor William A. Grobman, MD, from Northwestern University in Chicago, Illinois.

A performance measure proposed by the statement is the percentage of women who are candidates for TOLAC with whom discussion of the risk and benefits of TOLAC vs elective repeat cesarean delivery has been recorded in the medical chart.

"Given the onerous medical liability climate for ob-gyns, interpretation of The College's earlier guidelines led many hospitals to refuse allowing VBACs altogether," Dr. Grobman concluded. "Our primary goal is to promote the safest environment for labor and delivery, not to restrict women's access to VBAC."

Lamaze International's Statement on ACOG Guidelines

In response to the ACOG revised VBAC guidelines, Lamaze International has issued a statement commending the guidelines as a "step in the right direction" in reducing the number of cesarean deliveries. However, Lamaze International is "troubled by elements of the guidelines which continue to support practices that may increase risks and cause undue harm to mother and baby."

The organization questions ACOG's emphasis on uterine rupture, which is rare in VBAC. Lamaze International also points out that ACOG's use of certain language related to "immediately available" emergency resources may cause women to continue to have unfair access to VBAC.

Although Lamaze International takes issue with some of the elements of the revised guidelines, the organization is pleased with ACOG's emphasis on the benefits of a planned VBAC.

Practice Bulletin No. 115, "Vaginal Birth after Previous Cesarean Delivery," is published in the August 2010 issue of Obstetrics & Gynecology.

Obstet Gynecol. 2010;116:450-463.