Cesarean section is the delivery of a fetus through the abdominal wall and uterus. 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 child that follows 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
- Her doctor's experience
What makes the decision more complex is the fact that obstetrics professionals are struggling with the issue themselves.
Reducing the C-section Rate
A C-section is considered major surgery. Blood loss during a C-section is much greater than with vaginal delivery. The risk of serious complications like hemorrhaging and infection after delivery are also greater. It is not clear whether all cesareans are necessary. In fact, many organizations are advising doctors to work to lower the rate.
Looking at VBAC
Having a vaginal birth after a C-section (VBAC) is an area that researchers have been investigating. What are the benefits and risks? Some studies have concluded that there is not enough evidence to come up with a clear recommendation. Other studies, have found that VBAC is as safe as a planned C-section. Nevertheless, there are risks involved with VBAC.
Women who have a VBAC may have a higher risk of uterine rupture. Uterine rupture may put you and your baby at risk of harm including death, and may lead to an emergency hysterectomy. This complicates a mother’s recovery and can put an end to her childbearing—a result that may be less likely after C-section.
Examining the Reason for C-sections
The reason a woman had a cesarean in the first place often influences her decision about a trial of labor for her next delivery. For example, women who have 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 the pelvis is unfavorable for vaginal birth.
The reasons for scheduled cesareans can include:
- Fetal or maternal illness—This could make labor risky for mother and/or child.
- Fetal distress—This can be controversial because fetal monitors can be misread and because normal readings are subjective.
- Labor that fails to progress—This means labor does not progress normally.
- Placenta previa—The placenta blocks the cervix and is at risk of detaching before the baby is born.
- Baby in breech position—When the baby's head will not come out first, it is safest to deliver the baby via cesarean section.
- Multiple pregnancy.
- Cephalopelvic disproportion—This occurs when a baby's head is too large for the mother's pelvis. This is considered a controversial reason for C-section because the proportion is difficult to measure. Small pelvises do often accommodate large babies during labor.
- Infection in the mother.
- Previous C-section.
Getting the Experts' View
The American Congress of Obstetricians and Gynecologists (ACOG) feels that women who meet the following criteria are candidates to try VBAC:
- Have had 1-2 previous cesarean with a low-transverse uterine incision.
- 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.
- You cannot tell from the outside what type of incision you had in the uterus. You need to ask your surgeon.
- Women with a vertical incision should discuss whether a VBAC is appropriate, since data is mixed.
- 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 may 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 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.
Making an Informed Decision
It is possible to have a vaginal delivery after having had a cesarean section. However, you should work with your healthcare provider to determine which option is best for you given your prior and current health history.
American Congress of Obstetricians and Gynecologists
American Pregnancy Association
Canadian Women's Health Network
The Society of Obstetricians and Gynaecologists of Canada
American Congress of Obstetricians and Gynecologists. ACOG practice bulletin no. 115: vaginal birth after previous cesarean delivery. Obstet Gynecol. 2010 Aug;116(2 Pt 1):450-463. Reaffirmed 2015.
Armstrong C. ACOG updates recommendations on vaginal birth after previous Cesarean delivery. Am Fam Physician. 2011;83(2):215-217.
Cesarean section. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated November 23, 2015. Accessed February 3, 2016.
Reasons for a Cesarean birth. American Pregnancy Association website. Available at: http://americanpregnancy.org/labor-and-birth/reasons-for-a-cesarean. Updated August 2015. Accessed February 3, 2016.
Rossi AC, D'Addario V. Maternal morbidity following a trial of labor after cesarean section vs elective repeat cesarean delivery: a systematic review with metaanalysis. Am J Obstet Gynecol. 2008;199(3):224-231.
Trial of vaginal birth after cesarean (TOLAC). EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed. Updated November 3, 2015. Accessed February 3, 2016.
Vaginal birth after cesarean delivery: Deciding on a trial of labor after cesarean delivery. American Congress of Obstetricians and Gynecologists website. Available at: http://www.acog.org/~/media/For%20Patients/faq070.pdf. Accessed February 3, 2016.
VBAC: Vaginal birth after cesarean. American Pregnancy Association website. Available at: http://americanpregnancy.org/labor-and-birth/vbac. Updated August 2015. Accessed February 3, 2016.
Last reviewed February 2016 by Michael Woods, MD Last Updated: 2/3/2016