In the 1970s, when the cesarean section rate tripled, the medical mantra was "once a cesarean, always a cesarean." These days, most women who have had at least one child delivered by C-section will have to decide whether to try to deliver a subsequent child vaginally. This is a decision colored by a complex set of factors, including:

  • A woman's own experience
  • The reason for the original C-section
  • Her subsequent recovery
  • Her overall health
  • Her personal preference
  • The opinion and philosophy of her doctor

What makes the decision more complex is the fact that obstetrics professionals are struggling with the issue themselves.

Examining the Reason for C-sections

The reason a woman had a cesarean in the first place often influences, or even dictates, her decision about a trial of labor for her next delivery. For example, women who undergo C-sections after long and difficult labors that did not progress may face similar difficulties with subsequent deliveries. Some of these women will choose to deliver a subsequent baby by C-section, especially if their obstetrical consultant believes the pelvis is unfavorable for vaginal birth.

C-section may be “scheduled” or “unscheduled.” A scheduled section is planned in advance. The reasons for scheduled cesareans can include:

Reasons for unplanned or emergency cesareans include:

  • Labor that fails to progress—This means labor does not progress normally.
  • Fetal distress—This, too, can be controversial because fetal monitors can be misread and because "normal" is subjective.
  • Infection in the mother

Getting the Experts' View

The American College of Obstetricians and Gynecologists (ACOG) feels that women who meet the following criteria are candidates to try VBAC:

  • Have had one or two previous cesarean with a low-transverse uterine incision—You cannot tell from the outside what type of incision you had in the uterus. You need to ask your surgeon. The low-transverse incision allows muscle tissue to knit a scar that is much stronger than the older types of incisions. However, it generally takes more time to do, so doctors are not always able to use this method in emergency situations. Women with a vertical incision should not try VBAC.
  • Do not have any other uterine scars or ruptures, whether from previous cesareans or other surgeries

ACOG also specifies that whenever a woman is planning VBAC, a surgical team should be on hand in case an emergency C-section is necessary. In some healthcare settings, the lack of such a team would rule out any trial of labor for a VBAC.

The American Academy of Family Physicians (AAFP) largely agrees with ACOG, but does not agree on the necessity for an on-hand emergency surgical capability. Instead, they recommend that an explicit emergency management plan be developed for all women given a trial of labor after cesarean (TOLAC). This plan should be documented, presumably in the medical record. Risks should be discussed at length with women so that they can make a clearly informed consent.

AAFP emphasizes that certain factors (aged under 40, prior vaginal delivery—especially successful VBAC, obstetrically “favorable” cervix, spontaneous labor, and indication for cesarean that is unlikely to recur) make VBAC more likely after a TOLAC. They also indicate factors making successful birth less likely: gestational aged over 40 weeks, birth weight over 4 kg, and need to induce or augment labor.