Shoulder dystocia, in which the baby's shoulders won't move past the mother's bony pelvis during delivery, occurs in about 5 percent of births. Of these, up to a quarter of deliveries may result in an injury to the baby's brachial plexus, the nerves that control movement and sensation in the arm. As many as 10 percent of infants may sustain some permanent damage.
An obstetrician can perform one of several maneuvers to manipulate the position of either the mother or the baby when shoulder dystocia occurs. The Hopkins researchers found that turning the baby so its spine faces the mother's belly (a technique known as anterior Rubin's maneuver) requires less force than either turning the baby so its spine faces the mother's spine, or moving the mother's legs back to try to reduce the force of the baby's shoulders against the mother's pelvis.
These results are reported in the Jan. 4 issue of the American Journal of Obstetrics and Gynecology.
"Every obstetrician is likely to face this circumstance at some point in his or her career, and the longer the baby remains stuck, the higher the risk that the baby will suffocate," says Edith D. Gurewitsch, M.D., lead author of the study and an assistant professor of gynecology and obstetrics. "While further studies are necessary before we can make definitive recommendations on the use of one procedure over another, our initial lab results demonstrate that we can measure what is happening to the baby during birth, and that we can alter our techniques to create a safer environment for delivery - a goal shared by every obstetrician."
For the study, Gurewitsch performed 30 mock deliveries using a complex birthing device designed by