Japan to try prenatal detection test for Down syndrome


Several Japanese hospitals next month will start using a new prenatal blood test that can detect Down syndrome with an accuracy of more than 99 percent, hospital officials said Wednesday.

The National Center for Child Health and Development, Showa University Hospital and other medical facilities will use the new method, developed in the United States, to detect three types of chromosomal abnormalities in fetuses, including Down syndrome, by analyzing the DNA of pregnant women 35 or older, who face a higher risk of bearing children with chromosomal irregularities.

The new prenatal test is less risky than existing amniotic fluid tests, in which a thin needle is inserted into the abdomen, presenting a 0.3 percent higher risk of miscarriage.

The safer test is expected to raise the overall testing rate and possibly lead to an increase in abortions.

The hospitals aim to conduct the blood test on about 1,000 women over two years as part of their research. They will examine whether the new method helps the women refrain from undergoing amniocentesis, which will be unnecessary for those who test negative.

The blood examination will not be covered by health insurance and will cost ¥210,000. Those who have reached the 10th week of pregnancy or beyond are eligible, allowing women to be tested in the early stages of pregnancy, unlike amniocentesis, which must be carried out between the 15th and 18th week of pregnancy.

The national center said it is planning to draw up guidelines for conducting the prenatal blood test, which will involve the presence of several experts, at least 30 minutes of counseling and continued monitoring.

Haruhiko Sago, chief of the facility’s prenatal center, said it is “essential to provide women with enough counseling so they do not undergo the test without careful consideration.”

Sago also said the new method is already being used in Europe and the U.S. and that it is just a matter of time until Japan adopts it as well.

Kunio Tamai, chief director of the Japan Down Syndrome Society, said his organization is strongly opposed to jumping on the bandwagon from a bioethics standpoint and called for obtaining informed consent from parents-to-be.