Down syndrome live births following assisted reproductive technology in Japan: a nationwide survey between 2007 and 2016.

Purpose: The use of assisted reproductive technology (ART) and prenatal genetic testing have become more widespread in line with an increase in maternal age. However, the effect of the introduction of non-invasive prenatal testing (NIPT) in April 2013 on pregnancy outcomes in Japan, including the prevalence of Down syndrome live births following ART, has not been investigated. This study aimed to evaluate the trends in the prevalence of Down syndrome live births following ART in Japan. Methods: This population-based retrospective study used the Japanese nationwide ART registry. All clinical pregnancies resulting in live births, stillbirths, and termination of pregnancy (TOP) following ART from 2007 to 2016 were included. Pregnancy outcomes involving infants with Down syndrome were evaluated. Results: Among 351,808 pregnancies, the proportion of mothers with advanced age increased significantly from 2007 to 2016 (from 49.5 to 62.4% and 8.9 to 17.8% for mothers aged ≥ 35 and ≥ 40 years, respectively). The proportion of live births with Down syndrome was 77.3% in 2007, which remained consistent until 2012, but then decreased significantly to 45.1% after 2013 (P < 0.001). The prevalence of Down syndrome live births increased up to 2012 (19.5/10,000 live births), decreased significantly in 2013 (12.1/10,000 live births), and then remained almost stable (11.1–14.7/10,000 live births). Conclusion: The introduction of NIPT balanced the prevalence of Down syndrome live births following ART with recent increasing maternal age in Japan. [ABSTRACT FROM AUTHOR]