A breech birth is the birth of a baby from a breech presentation. In the breech presentation the baby enters the birth canal with the buttocks or feet first as opposed to the normal head first presentation.
There are either three or four main categories of breech births, depending upon the source:
* Frank breech - the baby's bottom comes first, and his or her legs are flexed at the hip and extended at the knees (with feet near the ears). 65-70% of breech babies are in the frank breech position.
* Complete breech - the baby's hips and knees are flexed so that the baby is sitting crosslegged, with feet beside the bottom.
* Footling breech - one or both feet come first, with the bottom at a higher position. This is rare at term but relatively common with premature fetuses.
* Kneeling breech - the baby is in a kneeling position, with one or both legs extended at the hips and flexed at the knees. This is extremely rare, and is excluded from many classifications.
As in labour with a baby in a normal head-down position, uterine contractions typically occur at regular intervals and gradually cause the cervix to become thinner and to open. In the more common breech presentations, the baby’s bottom (rather than feet or knees) is what is first to descend through the maternal pelvis and emerge from the vagina.
At the beginning of labour, the baby is generally in an oblique position, facing either the right or left side of the mother's back. As the baby's bottom is the same size in the term baby as the baby's head. Descent is thus as for the presenting fetal head and delay in descent is a cardinal sign of possible problems with the delivery of the head.
In order to begin the birth, internal rotation needs to occur. This happens when the mother's pelvic floor muscles cause the baby to turn so that it can be born with one hip directly in front of the other. At this point the baby is facing one of the mother's inner thighs. Then, the shoulders follow the same path as the hips did. At this time the baby usually turns to face the mother's back. Next occurs external rotation, which is when the shoulders emerge as the baby’s head enters the maternal pelvis. The combination of maternal muscle tone and uterine contractions cause the baby’s head to flex, chin to chest. Then the back of the baby's head emerges and finally the face.
Due to the increased pressure during labour and birth, it is normal for the baby's leading hip to be bruised and genitalia to be swollen. Babies who assumed the frank breech position in utero may continue to hold their legs in this position for some days after birth.