Dystocia due to the shoulders

Risk of shoulder dystocia in second delivery: does a history of shoulder dystocia matter?

“…This work was based on 26 observations described in literature at that time, and in Europe the maneuver of extracting the posterior arm was called the Jaquemer's maneuver after this giant in French obstetrics (23). However, in English scientific literature this maneuver was described by Barnum in a paper published in 1945, and is now commonly known as Barnum's maneuver (25).…”

Shoulder dystocia: incidence, mechanisms, and management strategies

“…The usual approach is to try to deliver the posterior arm first. This was described in English by Barnum 10 and is described in all of the textbooks. The operator follows the shoulder to the humerus and hopes to find the elbow and forearm of the posterior arm lying over the baby’s chest and, again, one grasps the forearm and sweeps it across the baby’s chest and outside the vulva.…”

“…Along the same lines, the increased intrathoracic pressure may not allow filling of the fetal heart. Barnum 10 hypothesized this as a cause of infant death due to shoulder dystocia and the hypothesis has been proposed 11 that hypovolemic shock may be the reason why some babies are unresuscitatable after shoulder dystocia. It has also been speculated that compression of the fetal neck may interfere with blood flow to and blood drainage from the brain, but this would not account for the failure of resuscitation in some cases.…”