Hyperextension of the fetal head in breech presentation: radiological evaluation and significance.

Damage of the cervical cord is not rare in breech delivery with hyperextension of the fetal head. Among 57 cases from the literature and one of ours in which the angle of extension could be measured on X-ray films, 20 had an extension angle greater than 90 degrees. Of these, 11 were delivered vaginally and included 8 cases of damage to the cervical cord. It is recommended that elective Caesarean section be performed when the angle of extension exceeds 90 degrees.