What is an external version?
If your baby is breech shortly before delivery, can he or she be moved into the correct position? Dr David Barrere tells you a little about a technique called external version.
My baby is frank breech at 37 weeks and I have been referred to a specialist for a external cephalic version. What does this procedure entail and what are the risks? -- Trudy
The expert answers
The breech presentation occurs in about 3 to 4 percent of pregnancies at term (37 weeks and beyond). External cephalic version is a procedure to aid in the turning of a baby from the breech position to the vertex (head down) position.
A woman who is 37 weeks or farther along in her pregnancy is considered a candidate for a version. Generally, most babies have turned by this time. If performed too early, a baby has the potential to "flip" back to the breech position, requiring re-version.
The success rate for a version ranges from 35-86 percent, depending upon the quoted source. The average is around 60 percent in experienced hands. The procedure should be performed in the hospital in case an emergent delivery is needed. Quite often, general OB/GYN's refer patients to a perinatologist (an OB/GYN that subspecializes in high risk pregnancies or special obstetrical procedures).
Some physicians give medications to relax the uterus (tocolytics). The most common are Terbutaline (Brethine), or Ritodrine. Occasionally, Magnesium sulfate is used. During the procedure, the baby is "encouraged" to turn by applying pressure to the mother's abdomen. Usually one hand helps to lift the baby out of the pelvis, while the other hand applies pressure to the baby's back to help it "somersault." During the manipulation, the uterus can tense up (contract), making the procedure more likely to fail. Tocolytics can be of help but are not always used. (Please note: this procedure should only be performed by a trained professional.)
In some cases, so much pressure is applied that the mother experiences severe pain. Some women tense their abdominal muscles which works against the physician. Therefore, another consideration is anesthesia, either in the form of an epidural or a spinal block. This makes the procedure more tolerable for the mother.
There are few risks to mother or baby during the procedure. The most common complication is a decrease in baby's heart rate. This is a short-lived phenomenon, however, if the slower rate persists, immediate delivery by cesarean section is warranted.
The main benefit of external version is the potential for a vaginal birth. Although vaginal breech deliveries are still performed, they are falling by the wayside. Most physicians feel more comfortable in delivering breech babies by cesarean section to eliminate the possible risks to the baby.