Prenatal diagnosis of aneuploidy and deletion 22q11.2 in fetuses with ultrasound detection of cardiac defects.

Objective: We report a prospective database evaluation of the occurrence of aneuploidy and deletion 22q11.2 after prenatal detection of cardiac abnormalities. To ensure the maximum inclusion, all cardiac defects were considered, with the exception of echogenic intracardiac foci.

Study Design: Prenatal specimens with ultrasound findings of cardiac defects were identified. Physicians were provided supplementary information that described the risk of deletion 22q11.2 syndrome if the karyotype was normal. On approval, fluorescence in situ hybridization was performed to identify the 22q11.2 microdeletion.

Results: Prenatal detection of cardiac abnormalities identified aneuploidy or unbalanced chromosome rearrangements in 41% of the cases that were studied. In those fetuses with normal karyotypes, 3% had the deletion 22q11.2.

Conclusion: These results indicate that prenatal ultrasound findings of congenital heart defects identify fetuses who are at increased risk for chromosome abnormalities. Fetuses with normal karyotypes should consider having fluorescence in situ hybridization studies for the microdeletion 22q11.2 syndrome. Chromosome and fluorescence in situ hybridization studies of family members should be recommended when a fetus is identified as having the deletion 22q11.2.