Trends in the prenatal diagnosis of trisomy 21 show younger maternal age and shift in the distribution of congenital heart disease over a 20‐year period

Abstract

Prenatal testing has changed greatly over the past two decades, which may affect the diagnosis of congenital heart disease (CHD) in Down syndrome. The present study aimed to analyze changes in the prevalence and distribution of CHD diagnosed via ultrasonography and fetopathology in 462 fetuses with trisomy 21 between two consecutive 10‐year periods (1999–2018), as well as the associations between CHDs, ultrasound markers, and extracardiac malformations. Overall, the frequency of cardiovascular malformations in trisomy 21 was 27.7 and 26.5%, and ultrasound identified 70 and 62% of CHDs during these periods. A profound increase in first‐trimester ultrasound findings and associated anomalies with CHDs (ventricular septal defect, Tetralogy of Fallot) since 2009 were observed. Second‐trimester nonstructural heart abnormalities were associated with ultrasound anomalies (74%) and major extracardiac malformations (42.9%). During both study periods, mothers carrying fetuses with CHD were significantly younger than those without CHD (p = 0.038, p = 0.009, respectively). Comparing the two 10‐year periods, there were no changes in the prevalence and detection of CHDs. Trend analysis revealed that, although the frequency of CHD remained stable, the diagnostic spectrum had shifted between the study periods. Detection of nonstructural heart abnormalities necessitates detailed follow‐up for cardiac/extracardiac malformations and chromosomal disorders.

Impact of a prenatal screening program on the Down syndrome phenotype: An interrupted time series analysis

“…A recent Dutch study similarly found the prevalence of atrial septal defect among newborns with Down syndrome to have increased following the introduction of first‐trimester combined screening (FTS) and non‐invasive prenatal testing, but, in contrast, reported the prevalence of AVSD to remain largely unchanged 10 . Potential temporal developments may be due to improved fetal echocardiography; however, a study from Hungary reported an unchanged prenatal detection rate of CHD in trisomy 21 fetuses from 1999–2008 to 2009–2018 11 . No studies have previously investigated the potential impact of prenatal screening and diagnostics on features of the Down syndrome phenotype other than malformations.…”

“… 10 Potential temporal developments may be due to improved fetal echocardiography; however, a study from Hungary reported an unchanged prenatal detection rate of CHD in trisomy 21 fetuses from 1999–2008 to 2009–2018. 11 No studies have previously investigated the potential impact of prenatal screening and diagnostics on features of the Down syndrome phenotype other than malformations.…”