Aim: To study the development and effectiveness of prenatal diagnostics for congenital heart defects (CHDs). To monitor the overall incidence of CHDs and the level of detection for individual types of fetal defects.
Methods: This retrospective cohort study retrieved data on ultrasound examinations of the fetal heart (fetal echocardiography), conducted by a gynecologist or pediatric cardiologist, and postnatal standardized examinations, conducted by a pediatric cardiologist, between 2011 and 2018. A pediatric cardiologist was present at all fetal autopsies and provided precise descriptions of the heart defect.
All fetuses and newborns with severe pathologies were included to identify associated genetic and extracardiac pathologies. Results: During the 8-year monitoring period, a total of 351 cases of severe heart defects were diagnosed in a population of 90,880 live births (3.9/1 000).
CHDs manifested as an isolated anomaly in 72% of cases (252/351). In total, 66% of CHDs (230/351) were detected prenatally and 34% (121/351) of CHDs remained undetected until after birth.
Screening effectiveness gradually improved over time; among the severe CHDs, 57% and 80% were detected prenatally in 2011 and 2018, respectively. Among all CHDs, the highest prenatal detection rates (80-100%) were observed for pathologies that affected ventricular morphology.
In the group of prenatally diagnosed CHDs, 47% (109/230) of families decided to terminate the pregnancy, 5% (10/230) of fetuses died intrauterine, and 48% (111/230) of families continued the pregnancy. Conclusion: CHDs mostly occurred as an isolated anomaly.
The most severe CHDs were detected prenatally. We found that prenatal detection of CHDs was highly effective and gradually improved over time.
The highest detection rate was for defects in the four-chamber projection. The participation of a pediatric cardiologist in fetal screening appeared to be necessary for determining the final diagnostics and for counseling the affected family.