Source:http://linkedlifedata.com/resource/umls/id/C0085988
NCI: An abnormal condition during labor when the diameter of the fetal head is larger than the maternal pelvic canal; thus it is dangerous or impossible for the fetus to progress to a vaginal method of delivery.,MSH: A condition in which the HEAD of the FETUS is larger than the mother's PELVIS through which the fetal head must pass during a vaginal delivery.