Trisomy 18 in a First-Trimester Fetus with Thoraco-Abdominal Ectopia Cordis.

Introduction: Fetuses with trisomy 18 will occasionally also have ectopia cordis. Case report: A routine ultrasound scan at 12 weeks' gestation revealed a large fetal anterior thoraco-abdominal wall defect with an extrathoracic heart and a liver-containing omphalocele. Chorionic villus sampling revealed a 47,XY,+18 karyotype. Additional anomalies detected after termination of the pregnancy included a cleft lip and palate and left radial agenesis. Conclusions: The prenatal diagnosis of ectopia cordis associated with aneuploidy can be made in the first trimester of pregnancy. An extrathoracic heart located in a liver-containing omphalocoele should be considered a thoraco-abdominal ectopia cordis rather than pentalogy of Cantrell.