Paediatric Cardiology Fellow University of British Columbia Vancouver, British Columbia, Canada
Background: Congenital heart disease (CHD) is the most common birth defect and can occur in isolation or be associated with extracardiac anomalies or genetic diagnoses. Identification of genetic diagnoses and extra-cardiac anomalies in patients diagnosed with prenatal CHD is important for prognostication, informed counselling, and shared decision-making. This study evaluates the use of genetic testing, incidence of extracardiac anomalies, and pregnancy outcomes in a prenatal CHD cohort over an eight-year period.
METHODS AND RESULTS:
Methods: As part of a quality improvement/quality assurance initiative at BC Children’s and Women’s Hospital, we retrospectively reviewed prenatal CHD cases from 2017 to 2024. Genetic testing modalities, results, associated extracardiac anomalies, and pregnancy outcomes were analyzed.
Results: 934 fetuses (12.7%) were diagnosed with CHD. Genetic testing was performed in 618 of the CHD cases (66.2%). Our data demonstrated an 18% increase in the use of genetic testing in CHD patients during the study period. Amniocentesis was the most common modality of testing (n= 247; 40%), followed by non-invasive prenatal testing (NIPT, n= 211; 34%) and serum integrated prenatal screening (SIPS, n= 100; 16%).
A confirmed genetic diagnosis was identified in 159 of the 618 tested (26%). Trisomy 21 was the most frequent diagnosis (n= 71; 44.7%), followed by trisomy 18 (n= 22; 13.8%), and 22q11.2 deletion (n= 10, 6.3%). Extracardiac anomalies were identified in 242 of the 934 CHD cases (26%).
715 (76.5%) cases resulted in live births, 19 (2%) experienced intrauterine fetal demise (IUFD), and 4 outcomes were unknown due to loss to follow-up. Termination of pregnancy occurred in 196 cases (21%). Of these, 58 terminations (37%) were in pregnancies with isolated CHD. Single ventricle anatomy was the most common lesion in terminated pregnancies, in both isolated CHD and CHD with genetic or extracardiac anomalies.
Conclusion: Genetic testing was performed in two-thirds of prenatally diagnosed CHD cases, with 26% yielding a genetic diagnosis. Trisomy 21, trisomy 18, and 22q11.2 deletion were the most common genetic anomalies diagnosed. Genetic diagnoses and extracardiac anomalies were seen in more than half of all CHD pregnancies that were terminated.
These findings underscore the importance of comprehensive genetic evaluation and identification of extracardiac anomalies in the prenatal management of CHD.
