Intrauterine depressed skull fractures of the newborn.

Intrauterine depressed skull fractures are reported only occasionally. In reviewing the literature it seems clear that pressure of the fetal head against the maternal bony structures, mainly the sacral promontory, accounts for most of the so-called "spontaneous" congenital depressed skull fractures. Rather than true fractures, they are focal congenital moulding depressions. On the other hand, trauma to the mother's abdomen and traumatic delivery are accepted pathological mechanisms for such lesions; most commonly they are ascribed to inexpert application of the forceps blades or undue force by the obstetrician at the time of birth. In some cases, however, uncomplicated spontaneous vaginal or cesarean section deliveries have surprisingly and unexpectedly yielded infants with depressed skull fractures. Three such cases are reported, and the literature is reviewed.