In most term pregnancies, the fetus will be in the vertex, or "head-down," position at delivery. When the fetus is not in this position, it is referred to as breech. Early in pregnancy the breech position is common.
In the vast majority of term pregnancies the fetus will be in the vertex, or "head-down" position at delivery. When the fetus is not in this position it is referred to as breech. Early in pregnancy the breech position is common. However, when the pregnant woman approaches her due date only 3% of babies will remain in the breech position. The majority of breech pregnancies in this country are delivered by cesarean section. However, as many as 17% are still delivered vaginally, although this number is quite variable at different hospitals.
Most of the time, the doctor can determine the position of the baby by feeling the pregnant woman’s abdomen. This is an examination known as "Leopold’s maneuvers". If this exam leads the doctor to believe that the baby is breech, an ultrasound study can be ordered to confirm this condition.
Although the cause of breech positioning is not always known, sometimes it can be linked to certain conditions. These conditions include premature labor, problems with the amount of amniotic fluid, problems with the placenta (the "after-birth"), tumors that change the shape of the uterus, and women who have had several previous pregnancies.
Under certain conditions a vaginal breech delivery can be attempted. However, as I stated earlier, most will be cesarean deliveries. The reason that so many breech babies are delivered by cesarean section is twofold. First of all, many physicians are concerned that there are increased risks for both mother and baby during a vaginal breech delivery. The actual scientific information on this topic is inadequate however, due to the difficulty in performing this type of study. And second, many obstetrical training programs no longer train doctors in the technique of vaginal breech delivery.
As an alternative to cesarean section, your doctor could attempt to manually turn the fetus out of the breech position. This procedure is referred to as "external version". It is best performed 3 weeks before the due date, and is usually done in the hospital while the fetus is closely monitored. External version is successful in up to 65% of breech pregnancies, although you must meet certain criteria in order to be considered a candidate for this procedure.
In summary, most pregnant women will never have to worry about their babies being breech. However, when this does occur a procedure known as "external version" can sometimes be attempted to convert the fetus to a "head-down", or vertex, position. If your baby remains in the breech position, most will be delivered by cesarean section, although vaginal delivery can sometimes be attempted if certain conditions are met.
1. Williams Obstetrics, 20th Edition, F. Gary Cunningham,M.D. et.al., Appleton & Lange, Stamford, Connecticut, 1997.
2. Management of the Breech Presentation, ACOG Technical Bulletin #95, August 1986.