For many years, the medical community believed that once a woman had given birth via a cesarean section that any additional babies she has must also be born via c-section. In fact, safe and successful vaginal deliveries are possible after a c-section, giving women the option to experience the childbirth process if they wish.
Experts estimate that 60 to 85 percent of women who had cesareans the first time around are able to have a normal labor and deliver vaginally their second, third or subsequent baby without incidence. Successful VBAC rates are higher for those women with non-recurring causes (such as a breech presentation with the first baby, but the favorable head-down position with the second) and those who have previously delivered vaginally.
There are many reasons a woman might choose to deliver a baby vaginally after a cesarean. Some women feel a sense of accomplishment with a vaginal birth, others have a medical condition which makes a repeat c-section riskier, while others do not want to repeat the lengthy and often painful recovery process associated with a c-section. Cesarean is also considered major surgery and, as such, is not without risks to mother and child, such as hemorrhage, infection and venous thromboembolism, and may place future pregnancies at increased risk for placenta previa, placenta accreta, uterine rupture, and peripartum hysterectomy. In addition, the process of labor and delivery helps prepare your baby for life outside the womb by helping him or her to expel much of the mucus and fluid from his lungs. There is also a decreased incidence of surgery-related fetal injuries (lacerations, broken bones) with a VBAC.
The type of uterine incision (which may differ from your abdominal incision) you received during your previous c-section will largely determine whether or not you will be able to attempt a VBAC. If you had a low transverse incision (horizontal, across the lower part of the uterus), there is an excellent chance you can deliver vaginally without incidence. However, if you had a classic incision (vertical, down the middle of your uterus), your obstetrician may not allow you to attempt a VBAC because this type dramatically increases your chances of uterine rupture. Uterine rupture is the most common problem associated with VBAC; however, it happens very rarely – in approximately 1 to 2 percent of VBACs. Your doctor will be able to assess your risk and advise whether VBAC is an option for you.
While the ACOG considers oxytocin use during VBAC acceptable, induction of labor, regardless of the method used, is increasingly recognized as a risk factor for uterine rupture, according to the AAFP. Recent VBAC studies have shown three to five times more ruptures among induced mothers compared with those having spontaneous onset of labor, and the AAFP recommends prostaglandins and oxytocin (Pitocin) be used with great caution during VBAC.
If you want to attempt a VBAC, talk to your obstetrician or midwife early in your pregnancy and make sure he or she is willing to perform one. Some obstetricians and an increasing number of hospitals have stopped performing VBACs due to concerns over legal action if something goes wrong and mother or baby is harmed. In fact, despite new research indicating the safety of VBAC, the percentage of women who had one fell from 28 percent in 1996 to 12.7 percent in 2002.
In 1999, the American College of Obstetricians and Gynecologists issued guidelines for VBACs that called for “immediate” availability of operating room teams to support every VBAC in case it required an emergency c-section. Hospitals and birthing centers were reluctant to keep a full surgery team on-call during a potentially lengthy labor and delivery and many prohibited VBACs as a result. However, the American Academy of Family Physicians recently revised its guidelines on trial of labor after cesarean (TOLAC) to state that “women should not be restricted only to facilities with available surgical teams present throughout labor. However, a management plan should be in place for each woman undergoing TOLAC in case of uterine rupture or other potential emergencies requiring rapid cesarean section. TOLAC should not be restricted only to facilities with available surgical teams present throughout labor since there are no studies that show these additional resources result in improved outcomes.”
A study released in the New England Journal of Medicine in December, 2004 followed nearly 34,000 women who were giving birth to their second child at 19 academic hospitals between 2000 and 2003. Approximately 18,000 of those women chose a VBAC, while 16,000 elected to have a second c-section. Of the women who attempted a VBAC, 74 percent of them succeeded in a vaginal birth, and 16 percent ended up having c-sections. Uterine rupture occurred in 0.7 percent of the VBAC women, seven babies (0.04 percent of all the planned VBAC) suffered hypoxia-related brain damage that was most likely caused by the uterine rupture, and two of those babies died (0.01 percent). However, twice as many women died during their second c-section as those who had a VBAC (7 and 3, respectively). The study concluded that a woman who chooses a VBAC over a second c-section increases her overall risk of adverse outcome by just 0.046 percent.
New research reported in the May/June 2006 issue of Annals of Family Medicine found that the maternal mortality rate remains about the same with either VBAC or repeat cesarean delivery, as does the neonatal mortality rate for infants whose birth weight is at least 1,500 grams (3.3 pounds). Smaller babies, however, have higher neonatal mortality rates with VBAC.
According to the AAFP, women who would like to attempt a VBAC should be informed that their chance for success is influenced by the following:
Positive Factors (increased likelihood of successful VBAC):
- Age – less than 40 years old
- Prior vaginal delivery (particularly prior successful VBAC)
- Favorable cervical factors
- Labor begins spontaneously
- Non-recurrent indication that was present for prior cesarean delivery
Negative Factors (decreased likelihood of successful VBAC):
- Increased number of prior cesarean deliveries
- Gestational age – baby is less than 40 weeks
- Birth weight – baby weighs less than 4,000 g (8.8 pounds)
- Labor must be induced or augmented
If you decide to attempt a VBAC and you wish to use pain medication, such as an epidural or narcotics, you should discuss this with your obstetrician well before your due date. Pain relief medications can be used with a VBAC; however, it’s important to use them wisely. Epidurals can slow labor and may increase your chance of needing another c-section. However, some studies indicate that if you delay an epidural until you are dilated at least 5 centimeters, your chances of having a cesarean delivery drop dramatically. Narcotics can lessen your anxiety and help relax you and, while they do not increase your chances of having a cesarean, they do affect your physical mobility and may affect your baby because they enter your bloodstream and therefore can cross the placenta.
There are plenty of ways you can help ensure you and your baby are safe during a VBAC delivery. Consider taking a childbirth refresher course to brush up on breathing and relaxation techniques that will help you labor efficiently and reduce stress on your body, or hire a doula to help coach you through labor. And during labor, let your doctor know immediately if you feel any unusual abdominal pain or tenderness.
The best way to prepare for your VBAC is to educate yourself and your partner about the benefits as well as the risks, and what you can expect. Read everything you can on the subject, ask plenty of questions of your doctor or midwife, and talk to other mothers who have experienced a VBAC, as well as those who have never had a cesarean.
If you want to try a VBAC but your doctor is unwilling to let you, and you are not prevented by any physical or medical reasons, then ask to be referred to one who will support you and be with you from the beginning of labor through delivery.