What are the problems with new prenatal diagnosis? Understand the disadvantages and approach them

What is New Prenatal Diagnosis?

NIPT (Non-Invasive Prenatal Testing) is a test that confirms chromosomal abnormalities in pregnant women through blood sampling. While prenatal diagnosis has existed before, a key difference with NIPT is that it can be performed from the 10th week of pregnancy.

NIPT is currently being conducted on a trial basis domestically, allowing detection of three chromosomal abnormalities including Down syndrome. Being able to undergo this test early without significant burden on pregnant women is considered a major advantage.

Issues with New Prenatal Diagnosis

NIPT appears to have benefits for pregnant women, but there are several issues to consider.

While NIPT is known for its high accuracy, the accuracy rates can vary depending on the results. For example, the negative predictive value of NIPT is 99.9%, but the positive predictive value is slightly lower. This means that even if the test results are positive, there could still be cases where the baby is born without abnormalities.

Need for Follow-up Tests if Positive Results

If chromosomal abnormalities are detected in the baby's womb with NIPT, it is common to undergo further diagnostic tests for confirmation. There are two types of precision tests typically conducted after NIPT:

Amniocentesis:
This involves inserting a needle into the uterus to collect amniotic fluid for examination. The test is known for its nearly 100% accuracy.

Chorionic villus sampling (CVS):
This test involves collecting cells from the chorionic villi, which are fetal-derived cells. While it can be performed earlier than amniocentesis, the availability of medical facilities offering this test is currently limited.

Both tests require direct collection of amniotic or chorionic villus cells, which carries a certain risk of miscarriage that should be kept in mind.

Concerns about New Prenatal Diagnosis Leading to Selective Abortion

NIPT, which helps determine whether a baby has chromosomal abnormalities, also raises ethical concerns. If NIPT reveals chromosomal abnormalities in the baby, there is a possibility that parents may choose to terminate the pregnancy. Indeed, some disability advocacy groups have expressed concerns about NIPT.

In response to such situations, the Japan Society of Obstetrics and Gynecology limits NIPT to detecting chromosomal abnormalities related to three diseases, including Down syndrome. Moreover, to ensure that NIPT does not lead to casual selective termination, the society specifies conditions under which the test can be performed:

• When the mother is aged 35 or older
• When there is a suspected risk of chromosomal abnormality in the baby
• When the mother has previously had a baby with chromosomal abnormalities

NIPT itself involves a simple blood test for pregnant women, making it accessible even at non-specialized medical facilities. However, the results of NIPT can significantly influence family decisions regarding the baby.

When NIPT indicates a possibility of chromosomal abnormalities in the baby, professional counseling and specialized support are strongly recommended.

What Comes After New Prenatal Diagnosis?

For families expecting a birth, it's natural to be concerned about the baby's health. Many people naturally wish for a healthy baby if possible. However, after casually undergoing NIPT, some families also consider opting for abortion if the baby is found to have a disability.

Reasons why families may choose abortion when there is a possibility of disability in the baby include:

• Concerns about the future of a child born with disabilities
• Anxiety about parenting a child with disabilities

In fact, a survey conducted five years after the introduction of NIPT reported the following:

• 58,000 people underwent NIPT testing
• 1,038 people tested positive, out of which 729 opted for artificial termination of pregnancy

Reviewing the above data reveals that NIPT not only helps families prepare mentally and practically for a baby with disabilities but also provides an opportunity to choose artificial termination of pregnancy.

Is Abortion Acceptable Due to Congenital Abnormalities?

In Japan, artificial abortion is permitted if pregnancy poses health or economic problems for the pregnant woman. However, there are no specific legal provisions regarding conditions related to the fetus.

Therefore, when abnormalities are detected in the unborn baby, some parents may choose artificial termination of pregnancy (referred to as "selective abortion" in medical terms). In Japan, amniocentesis has been performed since the 1970s, and based on the baby's health condition, some parents may have opted for termination of pregnancy.

Recently, ultrasound testing, a common examination for pregnant women, has become more precise. Currently, NIPT, which is performed in limited cases, is restricted to detecting only three types of chromosomal abnormalities. Therefore, even if NIPT shows a negative result, there is still a possibility that the baby may be born with some form of disability.

This raises the necessity for discussions regarding selective abortion.

Importance of Clarifying Purpose Before Taking NIPT

In Japan, delayed marriage has led to an increase in older mothers giving birth, which raises the likelihood of congenital disabilities such as Down syndrome. Therefore, knowing the baby's health status in advance through NIPT and similar tests can be advantageous. If abnormalities are detected with NIPT, it allows families to prepare in advance for welcoming the baby.

However, on the other hand, if the test results indicate a possibility of abnormalities, some individuals may consider the difficult decision of terminating the pregnancy. Initially, some may seek NIPT simply to understand the baby's health status, but the test results could significantly influence their decisions.

As mentioned earlier, a positive result from NIPT does not guarantee certainty, and even a negative result does not eliminate the possibility of other disabilities at birth.

Families opting for NIPT typically exhibit concern for the baby's health and look forward to the upcoming birth. However, in cases where a positive NIPT result leads to choosing termination, it can leave a profound emotional impact on the family.

While NIPT is a straightforward test, it's crucial not to take it lightly and to engage in thorough family discussions beforehand. It's essential to clarify individual perspectives and opinions on how to respond to each possible test outcome. Only then should a decision be made on whether to proceed with NIPT.

What to Do if New Prenatal Diagnosis Results are Positive?

Many parents naturally wish for their baby to be healthy. If a congenital anomaly is detected through NIPT or subsequent confirmatory tests, it is advisable to first undergo counseling.

Genetic counseling is recommended for issues related to genetics, including those identified through NIPT. Even individuals who are unsure about undergoing NIPT can benefit from genetic counseling. For those interested in learning more about NIPT, undergoing genetic counseling is highly recommended.

Conclusion

NIPT is a new prenatal screening method that detects chromosomal abnormalities in babies through maternal blood samples. Currently, NIPT tests for only three types of chromosomal abnormalities and does not definitively conclude whether the baby will have a disability.

Depending on NIPT results, some families may opt for elective termination of pregnancy. It's important not to take NIPT lightly but to discuss thoroughly as a family before deciding whether to undergo the test.