Breech Presentation and Delivery - Vaginal Breech Delivery
Delivery of a breech through the birth canal can be risky. Normally, with the head -first presentation, the largest part of the baby (the head) gradually stretches open the soft tissues and ligaments of the birth canal through the hours of labor. The fetal skull also gradually changes shape to fit into the mother's bony pelvis ("molding"). With a breech, the largest part is last, and the baby's head hasn't had a chance to "mold", or adjust to the pelvis by the time of birth. If it takes too long for the baby's head to be born after the body is out, he or she could have some damage from lack of oxygen. For this reason most breech births (90%) are by cesarean.
Breech presentations can safely be delivered vaginally with the following precautions:
- The baby should be a frank breech and near full- term. Any other leg position will not dilate the birth canal adequately.
- The head of the fetus should be flexed, with the baby's chin on his or her chest.
- The mother should have a "proven" pelvis, meaning she has delivered a child previously that was as big or bigger than the estimated weight of the breech fetus.
- The doctor or nurse/midwife should be experienced in attending breech births.
- Spontaneous and normally progressing labor.
- A healthy and well, mother and fetus.
Three types of vaginal breech deliveries are described, as follows:
- Spontaneous breech delivery: No traction or manipulation of the infant is used. This occurs predominantly in pre-term deliveries.
- Assisted breech delivery: This is the most common type of vaginal breech delivery. The infant is allowed to spontaneously deliver up to the umbilicus, and then maneuvers are initiated to assist in the delivery of the remainder of the body, arms, and head.
- Total breech extraction: The fetal feet are grasped, and the entire fetus is extracted. Total breech extraction should be used only for a non cephalic second twin(In a twin pregnancy where the first twin is in cephalic or head first presentation and the second twin does not assume the head down position).
It should not be used for singleton fetuses(only one fetus)because the cervix may not be adequately dilated to allow passage of the fetal head. If the feet prolapse through the vagina, treat expectantly as long as the fetal heart rate is stable to allow the cervix to completely dilate around the breech.