Cerebellar hypoplasia in the second trimester associated with microcephaly at birth

The antenatal diagnosis of microcephaly is most commonly made in the third trimester. Biometric measurements of the head of three or four standard deviations below the mean are suggestive of microcephaly. We report a case of microcephaly where abnormalities in intracerebral architecture, i.e. cerebellar hypoplasia, were noted early in the second trimester.