Ultrasound evaluation of the fetal central nervous system.

Evaluation of the fetal central nervous system is an integral part of any obstetric examination. Critical to the diagnosis of central nervous system abnormalities is a basic understanding of the normal fetal anatomy. Anatomic features of a normal ultrasound examination of the fetal central nervous system are discussed. In addition, the sonographic findings associated with a variety of major central nervous system anomalies are reviewed.