cross-birth

from The Collaborative International Dictionary of English v.0.48

Cross-birth \Cross"-birth`\ (kr[o^]s"b[~e]rth`), n. (Med.)
   Any preternatural labor, in which the body of the child lies
   across the pelvis of the mother, so that the shoulder, arm,
   or trunk is the part first presented at the mouth of the
   uterus.
   [1913 Webster]