Impact of prenatal screening on congenital heart defects in neonates with Down syndrome in the US

Abstract

Background: Non-invasive prenatal screening (NIPS) has fundamentally changed the screening process for Down syndrome (DS). Rates of complex congenital heart defects (CHD) have decreased in international studies but whether these shifts exist in the US is unknown.

Methods: Encounters for neonates with DS from 2007 to 2018 were obtained from the Pediatric Health Information System database. CHD were categorized as complex CHD, atrioventricular septal defects (AVSD), ventricular septal defects (VSD), and tetralogy of Fallot (TOF). Comparisons were made between pre-NIPS era (2007-2010) vs. post-NIPS era (2014-2018) and between states with low vs. high access to pregnancy termination as described by the Guttmacher Institute.

Results: Among 9122 patients, 6% had complex CHD, 22% had an AVSD, 22% had a VSD, and 4% had TOF. No difference in proportions of CHD was seen between eras. A small difference was observed in the proportion of AVSD between states with low vs. high access to pregnancy termination (23 vs. 17%, p < 0.001).

Conclusions: The proportion of CHD in patients with DS appears to be stable despite widespread adoption of NIPS in the US. Variations were observed between states with low vs. high access to pregnancy termination. Population based studies are needed to fully evaluate the current epidemiology of CHD in DS.

Impact: Through investigation of the Pediatric Health Information System database, this study assesses contemporary epidemiology of congenital heart disease among patients with Down syndrome. It has been suggested that improved prenatal screening for Down syndrome has altered the cardiac phenotype in international populations. Whether a similar shift also exists in the United States is unknown. In a contemporary United States cohort, a shift in the proportion or type of heart defects over the past decade was not observed. Regional differences in the proportion of heart defects were seen and may be due to differential access to prenatal care.