Alobar holoprosencephaly at 9 weeks gestational age visualized by two- and three-dimensional ultrasound.

We present the ultrasound detection of alobar holoprosencephaly (HPE) with cyclopia in an embryo of 9 weeks 2 days last menstrual period (LMP)-based gestational age; the crown-rump length (CRL) was 22 mm. The use of three-dimensional (3-D) ultrasound made additional diagnostic ultrasound tomograms possible, and the volume reconstructions improved the imaging and the understanding of the condition.