The number of people receiving the test has doubled! Current status of the new prenatal diagnosis

About NIPT

NIPT is a test that examines the cell-free DNA contained in the mother's blood during pregnancy to check for chromosomal abnormalities in the baby.

Chromosomes contain human genetic information, totaling 46 (23 pairs). It is known that abnormalities in number or structure can cause deformities or diseases.

Three types of chromosomal abnormalities detected by NIPT

There are several diseases associated with chromosomal abnormalities in babies, but currently, in approved facilities in Japan, NIPT is limited to diagnosing three chromosomal numerical abnormalities, including Down syndrome.

In Japan, 3.0 to 5.0% of newborns have congenital diseases, of which 25% are due to chromosomal abnormalities. Many fetal chromosomal abnormalities are particularly attributed to Down syndrome, making NIPT highly significant.

Previously, amniocentesis was conducted to confirm chromosomal abnormalities in the baby. However, amniocentesis involves inserting a needle directly into the abdomen to collect amniotic fluid, which can be burdensome for both the pregnant woman and the fetus. NIPT, on the other hand, can be easily conducted with about 10ml of blood, offering a significant advantage.

More than double the increase in people undergoing NIPT

NIPT, which has been fully introduced in Japan since 2013, has seen a 2.4-fold increase in the number of people undergoing testing over the past 10 years. Several factors contribute to the increase in people taking NIPT.

The first factor is the increase in "advanced maternal age" pregnancies, defined as pregnancies in women aged 35 and older, due to the trend of later marriages in Japan. It is no longer uncommon for women over 40 to give birth. Since chromosomal abnormalities in babies correlate with the age of the mother, interest in NIPT is likely increasing.

The second factor is Japan's declining birthrate issue. The number of children born to Japanese women has been decreasing year by year, resulting in fewer children. Consequently, it is natural for parents to want to ensure their one child is healthy.

In this way, the increase in people undergoing NIPT can be attributed not only to the simplicity of the test but also to social factors such as the aging population and declining birthrate in Japan.

NIPT test results are not a definitive diagnosis

Although NIPT can be easily conducted, a positive test result does not necessarily mean the fetus has a chromosomal abnormality. The accuracy (precision) of NIPT is 99.9%, so it is necessary to confirm the presence of chromosomal abnormalities in the baby through a definitive diagnosis using detailed tests such as amniocentesis.

NIPT allows for the confirmation of fetal chromosomal abnormalities relatively early in the pregnancy. Consequently, some people may choose not to continue the pregnancy if the test is positive. This is partly due to the high desire for a healthy baby and partly because the environment for raising children with disabilities is not fully developed in Japan.

Originally, NIPT aims to detect potential fetal disabilities early, but it can also lead to elective abortion. NIPT can be said to contribute to some extent to the "selection of life."

Fetal abortion is regulated by the Maternal Health Act, but there is no clear description of whether it is permissible to terminate a pregnancy if the baby has a disease or disability. Therefore, economic reasons often lead to abortion, as raising a child with a disease or disability may require considerable financial resources.

Given the rapid spread of NIPT, it is essential to consider it from an ethical perspective.

Medical institutions offering NIPT

When NIPT was first introduced, only 15 facilities offered the test, but by fiscal year 2018, the number had increased to 90. Simultaneously, the number of facilities not certified by the Japan Society of Obstetrics and Gynecology offering NIPT has also increased.

The Japan Society of Obstetrics and Gynecology recommends receiving NIPT at certified facilities, which must meet the following conditions:

• Having specialists in obstetrics, gynecology, and pediatrics
• Being able to conduct amniocentesis for definitive diagnosis and perform elective abortions
• Providing genetic counseling

among others.

While genetic counseling is not a mandatory requirement for NIPT, it can help address common concerns before and after the test.

On the other hand, the increase in non-certified facilities offering the test is believed to be due to the capacity limitations of certified facilities. Additionally, regional disparities in the availability of certified facilities contribute to the issue.

Many certified NIPT facilities are concentrated in medium-sized or larger cities, so there may be cases where no certified facilities are available in one's region.

Non-certified facilities offer the convenience of easily undergoing NIPT. Test results can be conveniently accessed by mail or smartphone.

What to do if NIPT results are positive

NIPT screens for chromosomal abnormalities in the fetus and enables early disease detection. If abnormalities are detected early during pregnancy, treatment can begin shortly after birth.

However, many people may feel confused if NIPT reveals chromosomal abnormalities in the baby. Some may even consider terminating the pregnancy if NIPT results are positive.

In recent times, information is readily available on smartphones and computers. However, relying solely on the internet can result in biased information. If NIPT results are positive, it might be beneficial to read books about children with disabilities.

Many regions have family groups with children with chromosomal abnormalities and nursery schools that provide special education for children with disabilities. If you are unsure about what to do after a positive NIPT result, visiting these places can be helpful.

Initially, everyone feels anxious about raising a child with disabilities. Seeing children with disabilities firsthand and hearing experiences from their families can help clarify your thoughts on disabilities and children's happiness.

Based on this understanding, consider the current situation of raising children with disabilities and make an informed decision about the path you want to take.

Summary

In Japan, the trend of later marriages and births is increasing, leading to a growing interest in NIPT for checking for chromosomal abnormalities in babies beforehand. Although the statistical likelihood of chromosomal abnormalities in newborns is low, the test can reveal potential abnormalities in the fetus.

Among those who have undergone testing, some positively view NIPT for allowing them to prepare mentally in advance, while others regret knowing about the baby's disability.

Undergoing NIPT can lead to significant decisions. It is important to consider beforehand what to do if chromosomal abnormalities are detected in the baby.