Congenital heart diseases and genetics: a prospective cohort study

In our study we aim to assess the prevalence of genetic disorders among congenital heart disease (CHD), investigating during pregnancy karyotype, chromosomal microarray analysis and genomics by invasive prenatal test. A prospective cohort study was conducted in the Prenatal Diagnosis Unit in a University referral hospital for high-risk pregnancies, in Rome, Italy. All singleton pregnancies with a diagnosis of complex heart disease who underwent invasive prenatal test between January 2020 and March 2022 were enrolled for the study. Complex CHD included were divided into: -left-sided obstructive lesions: -right-sided obstructive lesions; -mixed type of congenital heart diseases; -others (cardiomyopathy, tumours). The primary outcome evaluated was the presence of genetic alteration in congenital heart disease. Secondary, obstetrical and perinatal outcomes were investigated. 89 fetuses were enrolled in the present study. Villocentesis and amniocentesis were performed in 12.35% and 87.65% of cases respectively. CHD was an isolated impairment in 65.2% of cases and a soft marker was present in 29.2% of cases. Urogenital and gastrointestinal anomalies were most frequently associated, in 10.1 and 9% of cases respectively. A genetic anomaly was found in 18/89 (20.2%) of cases. A significant correlation has been found between atrioventricular canal defect and karyotype anomalies (T21, T13, T18) but not for ventricular septal defects. Non-karyotype anomalies were not significantly associated with any CHD but were found in 15.8% of cases. 37% of women decided for termination of pregnancy. Cytogenetics and molecular investigations should be always offered to the couple to guarantee an informed choice about the ongoing pregnancy, to formulate the recurrence risks and to guide the most appropriate obstetric management and genetic counselling.