Incidence, distribution, disease spectrum, and genetic deficits of congenital heart defects in China: implementation of prenatal ultrasound screening identified 18,171 affected fetuses from 2,452,249 pregnancies

BackgroundCongenital heart defects (CHDs) are the most common birth defects. Assessment of the incidence, distribution, disease spectrum, and genetic deficits of fetal CHDs in China is urgently needed.MethodsA national echocardiography screening program for fetal CHDs was implemented in 92 prenatal screening-diagnostic centers in China.FindingsA total of 18,171 fetal CHD cases were identified from 2,452,249 pregnancies, resulting in 7 center dot 4/1,000 as the national incidence rate of fetal CHD. The incidences of fetal CHD in the six geographical regions, the southern, central, eastern, southwestern, northern, and northwestern, were 7 center dot 647 (CI: 7 center dot 383-7 center dot 915), 7 center dot 839 (CI: 7 center dot 680-8 center dot 000), 7 center dot 647 (CI: 7 center dot 383-7 center dot 915), 7 center dot 562 (CI: 7 center dot 225-7 center dot 907), 5 center dot 618 (CI: 5 center dot 337-5 center dot 906), and 4 center dot 716 (CI: 4 center dot 341-5 center dot 108), respectively, per 1,000 pregnancies. Overall, ventricular septal defect was the most common fetal CHD, accounting for 17.04% of screened pregnancies nationwide, and tetralogy of Fallot, the most common anomaly in the major defect of fetal CHD, was the second most common, accounting for 9.72%. A total of 76.24% cases of fetal CHD were found to be an isolated intracardiac single defect. The remaining 23.76% of cases of fetal CHD had multiple heart defects. Among all extracardiac malformations, the central nervous system (CNS) was the most common tissue with extracardiac anomalies associated with CHD, accounting for 22.89% of fetal CHD cases. Chromosomal karyotyping identified trisomy 18 as the most common chromosomal abnormality in fetal CHD. We also documented that CHD-containing syndromes could be identified with a comprehensive approach integrating prenatal ultrasound, MRI, pathological autopsy, and cytogenetics and molecular genetics.ConclusionImplementation of prenatal echocardiography as a practically feasible platform to screen fetal CHD will reduce the financial and emotional burden of CHD, which may facilitate intrauterine and neonatal intervention of CHD.

Automated summary

A national echocardiography screening program for fetal congenital heart defects (CHDs) was conducted in China to assess the incidence, distribution, and disease spectrum of CHDs. Ventricular septal defect was the most common CHD, followed by tetralogy of Fallot. Majority of the CHD cases were isolated intracardiac single defects, while some had multiple heart defects. The central nervous system was the most common extracardiac tissue associated with CHDs, and trisomy 18 was the most common chromosomal abnormality.