Antenatal diagnosis of alobar holoprosencephaly.

A twenty-year-old second gravida presented to the department of radiodiagnosis for routine obstetric ultrasound examination. Ultrasonography revealed a live fetus of 17 weeks with absent falx, fused thalami, monoventricle, proboscis, and cyclopia. Fetal MRI was performed and the findings were confirmed. Even though ultrasonography is diagnostic in the detection of fetal anomalies, MRI plays a vital role due to its multiplanar capability and excellent soft tissue resolution. The importance of presenting this classical case of alobar holoprosencephaly is to sensitize the clinicians and radiologists to the imaging manifestations of holoprosencephaly and to stress the importance of early diagnosis. If diagnosed in utero at an early stage of pregnancy, termination can be performed and maternal psychological trauma of bearing a deformed fetus can be avoided.