While determining a cause of Cerebral Palsy can be difficult, determining the cause of shoulder dystocia is a much more simple process. This injury to the brachial plexus during delivery occurs when a baby's head enters the mother's birth canal while the rest of the newborn's body is an awkward or rigid posture. The shoulder of the newborn becomes lodged against the bone structures behind the birth canal. The result is that the nerves around the shoulder get torn or damaged, and the infant suffers from paralysis of the area.
Shoulder dystocia happens often enough to the point that attending doctors should be aware of the established warning signs that it could occur. A mother who has been conscientious about her prenatal care has given the doctor many opportunities to spot possible dystocia related complications when the birth occurs. If a mother has an abnormal pelvic anatomy, gestational diabetes, or is a person of short stature, then any one of these can be considered a risk. Shoulder dystocia is also more common among women who deliver larger than average babies. The average rate for dystocia among infants weighing 9 pounds or more is 9 percent, and with doctors frequently employing ultrasounds, a larger than average baby should be noticed well before the birth. A possible episode of shoulder dystocia is rarely something that simply happens "out of the blue."
There are also several methods that a doctor should use to safely dislodge the shoulder and successfully deliver the baby. These maneuvers include the McRobert's maneuver, which is simply pushing the mother's legs further apart by applying pressure at the knee toward the head. Other maneuvers include gentle suprapubic pressure from the side, with the avoidance of any pressure between the breasts and abdomen. Doctors should avoid this type of pressure (called fundal pressure) at all times during a dystocia episode. If these procedures are unsuccessful, the obstetrician should attempt to rotate the lodged shoulder with gentle pressure using the Wood's or Rubin maneuver. An episiotomy may provide additional outlet access. All maternal pushing should be terminated as well when shoulder dystocia is encountered. If an obstetrician applies excessive pressure, either with hands, forceps, vacuum extraction or other equipment used during delivery, nerves in the brachial plexus can be torn and damaged, resulting in partial or complete paralysis to the baby's shoulder, arm and/or hand.
Shoulder Dystocia is an event that is both foreseeable and preventable, and any competent doctor should be prepared for its occurrence.