This is a case of trisomy 18 in a 27-year-old primigravida, with unremarkable family history and no environmental exposure. She was referred to our unit because of fetal abnormalities at 34th week of pregnancy and the ultrasound revealed polyhydramnios, vermian hypoplasia, overlapping fingers, IUGR and an abnormality of the brain. Karyotype confirmed regular trisomy 18.

Figures 1, 2. Facial profile with micrognathia (left); and deformed ear (right).

Images 3, 4. Possible hypoplasia of the cerebellar vermis.

Images 5, 6. Transverse plane through fetal kidneys showing pyelectasia (left); and dilated hypotonic urinary bladder (right).

Images 7, 8. Overlapping fingers.