Abnormalities of the Fetal Head and Neck

Fetal head and neck abnormalities can be reliably assessed using a combination of 2D and 3D ultrasound. The accuracy of imaging depends to a large extent on gestational age. Magnetic resonance imaging (MRI) has evolved as a useful adjunct to ultrasound particularly for prenatal diagnosis of fetal head and neck anomalies. Intrauterine MRI improves diagnostic accuracy for fetal brain abnormalities and often leads to changes in management. MRI can be used to refine diagnoses in complex cases where ultrasound imaging is unclear or cannot determine the precise diagnosis. Some fetal neck masses can result in neonatal respiratory compromise. An ex utero intrapartum treatment (EXIT) procedure may be required if a neck mass is causing tracheal occlusion. Polyhydramnios can occur if there is oesophageal compression. When a fetal head and neck abnormality is detected, appropriate counselling regarding diagnosis, prognosis, and treatment options is crucial in allowing the patient to make an informed and timely decision in relation to pregnancy management. This review contains 14 figures, 3 tables, and 68 references. Key words: Intracranial abnormality, anencephaly, encephalocele, cystic hygroma, fetal neck mass, ventriculomegaly, fetal goiter, Craniosynostosis, Agenesis of the corpus callosum, Holoprosencephaly, EXIT