Finding the fetus in a breech presentation through ultrasound or by feeling the mother's abdomen around 20 weeks into the pregnancy is of no important consequence and should not prompt any special concern. Generally the fetus will rotate to a cephalic presentation by term. If, however, the fetus is still in a breech presentation 37 weeks into the pregnancy, it is reasonable to attempt to turn the fetus to a cephalic presentation to avoid the problem of having a breech baby at the onset of labor a week or two later. Though less likely, some fetuses will still rotate spontaneously after 37 weeks. On the other hand, some fetuses successfully rotated by ECV, may flip back before the mother goes into labor.
External Cephalic Version (ECV)
External cephalic version is a procedure for turning the fetus from a breech to a cephalic (head-first) presentation by manipulation through the mother's abdomen. This procedure is successful in keeping the fetus in a cephalic presentation 50 to 70% of the time. In most medical centers, the protocol for ECV includes the following steps:
- obtaining an ultrasound and non-stress test to make sure the fetus is healthy prior to the procedure;
- administering a drug, usually terbutaline (Brethine), to relax the muscles of the uterus. This may be unnecessary for women who have had a prior pregnancy;
- monitoring the fetus's heart rate by ultrasound during the procedure;
- attempting to roll the fetus forward or backward by lifting and pushing the fetus's buttocks upward through the mother's abdominal wall, while guiding the head toward the pelvis; and
- obtaining a non-stress test after the procedure, even if it is not successful, to ensure that the fetus is still healthy and tolerated the procedure.
ECV is less likely to work if:
- the mother has never had a baby before;
- the mother is obese;
- the fetus is lying on its back rather than on its side; or
- the amount of amniotic fluid around the fetus is reduced.
Women who are Rh-negative, and who are having an attempted ECV should receive Rh immune globulin (RhoGam) if delivery is to be delayed by more than 48 to 72 hours.
If the attempted ECV is unsuccessful, some doctors make a second attempt a few days to one week later, or when placing an epidural block for delivery. Trying to turn the fetus once an epidural block has been placed avoids most of the discomfort associated with attempted ECV and allows a cesarean section to be performed immediately if the attempt fails. If the fetus flips back after a successful ECV, the doctor can attempt to perform the ECV a second time. At this point, labor may be induced while the fetus is in cephalic presentation so that it does not flip back again, which is called an unstable lie.