Objective: To determine the incidence of aneuploidy among fetuses with congenital heart disease diagnosed in utero.
Methods: From June 1988 through December 1991, 502 fetuses at risk for congenital heart disease underwent fetal echocardiography. Fetal karyotyping was performed whenever a cardiac anomaly was diagnosed. Autopsy reports, postnatal echocardiograms, and angiograms were obtained to confirm the diagnosis.
Results: Congenital heart disease was found in 31 of 469 fetuses with complete follow-up. Fifteen of these 31 fetuses (48%) were found to have an abnormal karyotype: five of 17 (29.4%) with isolated cardiac anomalies and ten of 14 (71.4%) with cardiac and extracardiac anomalies. Detected chromosomal abnormalities included six trisomy 21, four trisomy 18, four trisomy 13, and one triploidy 69,XXX. Atrioventricular septal defects and ventricular septal defects were the cardiac malformations most often associated with abnormal karyotypes (77 and 71%, respectively).
Conclusions: The risk of aneuploidy associated with fetal cardiac anomalies is much greater than that associated with elevated maternal age; therefore, fetal karyotyping should be offered whenever a cardiac defect is diagnosed. Advanced gestational age should not represent a deterrent, because the discovery of a lethal trisomy in a fetus with a cardiac malformation can affect dramatically the prognosis and the obstetric and neonatal management. We believe that a screening view such as the four-chamber view should now be included routinely in obstetric ultrasound examinations.