VAGINAL BIRTH AFTER CESAREAN
What is a vaginal birth after cesarean delivery (VBAC)?
Vaginal birth after cesarean section is becoming more and more common. What was always said — "once a cesarean, always a cesarean" — no longer holds true. The view "once a cesarean, always a cesarean" dates from the time when the uterus was opened at cesarean section through a vertical incision. Since the early 1970s, with the now standard horizontal incision in the uterus, the chance of rupture has been reduced to a minimum (less than 0.5%).
In most developed countries, however, a previous cesarean section is not an absolute indication for delivering by cesarean in the next pregnancy as well. The alternative is vaginal birth after cesarean (VBAC).
Many women who wanted a vaginal birth but had to deliver by cesarean want to have their second child vaginally. For a woman to be able to give birth vaginally after a cesarean, however, certain conditions have to be met. Most women with one previous cesarean and no other complicating factor are candidates for a vaginal birth. A planned vaginal birth after a previous cesarean has a success rate of between 60% and 80% — entirely comparable with the rate of successful vaginal birth in first-time mothers. If the woman had already had a vaginal birth before her cesarean, the success rate reaches 87–90%.
What are the main advantages?
The main advantages of vaginal birth after cesarean are that the mother recovers more quickly, her hospital stay is shorter, and she avoids infection, injury (to the bowel, the bladder and so on), blood loss, blood clots in the vessels and postoperative complications. The mother has a more active role in caring for her newborn in the first hours of its life. Finally, it leaves open the possibility of many future pregnancies, because repeated cesarean sections carry risks relating to the strength of the uterus, injury to neighbouring organs (bowel and bladder) and the position and texture of the placenta (a risk of placenta previa and/or placenta accreta). There are certainly benefits for the baby as well, such as avoiding iatrogenic prematurity and reducing cases of persistent pulmonary hypertension. Vaginal birth always prepares the baby for life outside the womb.
What are the main conditions?
Certain conditions must of course be met for a vaginal birth to succeed. Some of the main ones are choosing an obstetrician experienced in such cases, and a maternity unit and delivery room that are fully equipped, with the ability to perform an immediate cesarean section if and when it is needed.
In addition, from the early stages of pregnancy through to the last month, weekly ultrasound (and Doppler) examinations of the baby are essential; from the 32nd week onwards the baby should be monitored regularly with cardiotocography (NST); induction of labor with prostaglandins or oxytocin should be avoided, because it significantly increases the risk of uterine rupture; and finally, after the placenta has been delivered, the cavity of the uterus — and especially the anterior wall — must be examined with the fingers.
It matters a great deal to know the exact reason for the previous cesarean section. If the reason was cephalopelvic disproportion or breech presentation, the woman can attempt a vaginal birth and indeed has a high chance of success. The same applies if the reason for the cesarean was changes in the baby's heart rate due to the cord being around the neck. There are, without question, contraindications as well, which centre chiefly on the incision in the uterus: it must be a low transverse one, and any other uterine incision is an important contraindication, as is a previous uterine rupture or a previous myomectomy with an incision reaching the uterine cavity. At least a year must have passed since the last cesarean section, or the chance of a successful vaginal birth is reduced. It should be planned for around the 38th week of pregnancy. An epidural helps the whole process considerably, because it allows the woman to relax and also helps the cervix to dilate.
Attempting a vaginal birth after cesarean (VBAC) is not unrealistic. If the conditions described above are met, the chance of a vaginal birth succeeding is around 60%. The main reason for trying is the enormous sense of satisfaction and achievement that comes with a vaginal birth after a cesarean. The woman feels she has achieved what she wanted from the first time she became pregnant. It gives her confidence that future births will also be vaginal. Finally, it allows her partner to take an active part in the birth alongside her and their doctor, which extends that sense of fulfilment to the couple and the family.