Cloacal dysgenesis sequence in the first trimester of gestation

The autopsy data in 17 first trimester fetuses with cloacal dysgenesis sequence are presented. The prenatal ultrasound showed dilated bladder. Cytogenetic analysis of 16 cases carried out by chorion villus sampling or obtained from post-abortion tissues demonstrated normal karyotype. The complete autopsy revealed cystic dilated cloaca, smooth perineum, absence of anal opening and a phallus-like structure. There were 12 cases with isolated cloacal dysgenesis sequence and 5 cases with multiple malformations. In the latter group cloacal dysgenesis were associated with VACTERL association and non-classified multiple malformation complex.