Current status of non‐invasive prenatal testing in Japan

Abstract

Aim The purpose of this study was to report the 3‐year experience of a nationwide demonstration project to introduce non‐invasive prenatal testing (NIPT) of maternal plasma for aneuploidy, and review the current status of NIPT in Japan. Methods Tests were conducted to detect aneuploidy in high‐risk pregnant women, and adequate genetic counseling was provided. The clinical data, test results, and pregnancy outcomes were recorded. We discuss the problems of NIPT on the basis of published reports and meta‐analyses. Results From April 2013 to March 2016, 30 613 tests were conducted at 55 medical sites participating in a multicenter clinical study. Among the 30 613 women tested, 554 were positive (1.81%) and 30 021 were negative (98.1%) for aneuploidy. Of the 289, 128, and 44 women who tested positive for trisomies 21, 18, and 13, respectively, and underwent definitive testing, 279 (96.5%), 106 (82.8%), and 28 (63.6%) were determined to have a true‐positive result. For the 13 481 women with negative result and whose progress could be traced, two had a false‐negative result (0.02%). The tests were performed on the condition that a standard level of genetic counseling be provided at hospitals. Conclusion Here, we report on the 3‐year nationwide experience with NIPT in Japan. It is important to establish a genetic counseling system to enable women to make informed decisions regarding prenatal testing. Moreover, a welfare system is warranted to support women who decide to give birth to and raise children with chromosomal diseases.

Equipoise of recent estimated Down syndrome live births in Japan

“…By comparison, the prenatal screening rates in other advanced countries are reportedly as follows: less than 30% in the Netherlands, 74% in the United Kingdom, and more than 90% in Denmark (Crombag et al, ; Vassy, Rosman, & Rousseau, ). As in other countries, NIPT has become available in Japan (Sago & Sekizawa, ; Samura et al, ). With this increasing availability of prenatal genetic testing in Japan, a higher population of DS fetuses would be detected and the equipoise of DS live births at present might be broken.…”

Age-related anxiety and self-assessment of perinatal depression risk: A web-based study

“…These results suggested that many pregnant women were most concerned about the safety of their children Pregnant women aged 35 years or older and those with evidence of chromosomal abnormalities could participate in the study. Based on a recent report, 61,330 tests were performed over a 3-year period [14]. Since the need for prenatal diagnosis for pregnant women continued to grow, the JSOG announced that the availability of NIPT would be extended to general obstetrical clinics in 2019 [15].…”

A case of Ewing's sarcoma identified via noninvasive prenatal testing

“…Over 60 000 tests were performed by the Japan NIPT consortium in the first 6 years since its introduction, with more than 90% of cases analyzed via massively parallel sequencing (s‐MPS) for the DNA analyses. Among the pregnant women tested, 1.8%, 97.9%, and 0.3% obtained positive, negative, and inconclusive results, respectively . The positive predictive value of trisomy 21 was over 96%, and the negative predictive value of three trisomies was <1 in 10 000 .…”

“…Among the pregnant women tested, 1.8%, 97.9%, and 0.3% obtained positive, negative, and inconclusive results, respectively . The positive predictive value of trisomy 21 was over 96%, and the negative predictive value of three trisomies was <1 in 10 000 . Previously, we conducted NIPT analysis of cfDNA in maternal plasma comprising maternal and placental DNA, and the median fetal fraction of samples having euploid results was 13.7% .…”