The dynamic fetal brain.

PURPOSE: To evaluate fetuses with normal intracranial anatomy in the second trimester that became abnormal in the third trimester.

METHODS

We sonographically examined 6 fetuses with a normal second-trimester head sonogram that presented later in pregnancy with an abnormal head sonogram.

RESULTS

Four categories of intracranial pathology were depicted: obstructive hydrocephalus, intraventricular intracranial hemorrhage, non-intraventricular intracranial hemorrhage, and porencephaly.

CONCLUSIONS

Despite a normal midtrimester intracranial examination, evaluation of the fetal intracranial contents should be undertaken in subsequent sonographic examinations, because significant pathology can develop spontaneously.