Semilobar holoprosencephaly with associated cyclopia and radial aplasia: first trimester diagnosis by means of integrating 2D-3D ultrasound.

INTRODUCTION

Holoprosencephaly (HPE) is commonly associated with facial malformations. We present a case of semilobar HPE associated with distal limb defect which was detected at 12 weeks of gestation.

CASE

The fetus had a crown-rump length of 60 mm (12 weeks-4 days), had nuchal translucency thickness of 1.5 mm. Initial two-dimensional (2D) ultrasound revealed the absence of nasal bone, decreased BPD and abnormal profile. Transvaginal 2D ultrasound was effective in the detection of HPE (partially absence of the interhemispheric fissure, fused thalami, the choroid plexuses were not visualized bilateraly: absent 'butterfly' sign), cylopia, absence of the nose and unilateral radial aplasia. Three dimensional (3D) ultrasound provided a better visualization of the associated anomalies. The necropsy result confirmed the sonographic findings: the diagnosis was semilobar HPE, cyclopia, absence of the nose, and the absence of the radius and the thumb in the left arm.

DISCUSSION

Transvaginal 2D sonographic examination is effective in detection of the cases with HPE at first trimester. Fetal morphological study through 3D ultrasound may facilitate the diagnosis of associated anomalies.