Prenatal ultrasonographic features of the Pena-Shokeir I syndrome and the trisomy 18 syndrome

The prenatal ultrasonographic features found in two cases each of the Pena‐Shokeir I and the trisomy 18 syndromes are described. All four cases were referred for ultrasonographic evaluation of polyhydramnios, clinically detected in the third trimester. A detailed ultrasonographic study of the craniofacial structures, intrathoracic organs, and limbs showed scalp edema, multiple ankyloses, camptodactyly, rocker‐bottom feet, cardiac arrhythmias, and lung hypoplasia. Chromosome analysis showed trisomy 18 in two cases; in the other two cases the diagnosis of the Pena–Shokeir I was confirmed after delivery. The similarity of the two syndromes with respect to ultrasound findings is discussed.