- Introduction
- When Will I Get the Results of the Prenatal Test?
- Is there any age limit for NIPT (New Non-invasive Prenatal Testing)?
- When was NIPT (New Non-invasive Prenatal Testing) introduced?
- What is the probability of finding out the gender of the baby with NIPT (Non-invasive Prenatal Testing)?
- Things to Keep in Mind When Undergoing Prenatal Testing
- Summary
Introduction
Many pregnant women are very excited about conceiving a child, but are also worried about whether the child is growing healthily and whether there are any problems. Many are also concerned about the gender of the baby.
In this article, we will discuss the tests that can be performed during pregnancy at such times and when the results will be released.
When Will I Get the Results of the Prenatal Test?
There are several types of tests that can be performed during pregnancy. The following is an explanation of the different types of tests available and when each test result is released.
When Will I Get the Results of the Prenatal Checkup?
During a prenatal checkup, the baby is examined by transvaginal ultrasound in the early stages of pregnancy and by transabdominal ultrasound from the mid-term onward. The results are obtained during the checkup, but are not as accurate as other examinations because they are performed by ultrasound.
When Will I Get the Results of the Amniotic Fluid Test?
Amniotic fluid testing is a definitive test, but because amniotic fluid is collected, there is a risk of miscarriage or stillbirth.
The test can be taken after 15 weeks of pregnancy. Once the amniotic fluid is collected, it needs to be cultured for about two weeks to grow fetal cells. The test will then be performed, so it will take about 3 weeks at the earliest to get the results.
When will I get the results of the NIPT (New Non-invasive Prenatal Testing) test?
NIPT (New Non-invasive Prenatal Testing) is a new prenatal genetic testing using maternal blood, also called maternal blood fetal chromosome testing. The test uses blood samples from the mother to check for chromosomal abnormalities such as Trisomy 21 (Down syndrome), Trisomy 18 (Edwards syndrome), and Trisomy 13 (Patau syndrome).
Because the test utilizes only the mother’s blood sample, it is safe to perform and has a higher positive/negative predictive value than other non-definitive tests.
Most NIPT (New Non-invasive Prenatal Testing) tests are performed by overseas laboratories, so it takes one to two weeks to receive the results.
Differences in NIPT by each Facility
Although NIPT (New Non-invasive Prenatal Testing) generally takes about two weeks to receive the results, some medical institutions may be able to perform the test at a domestic laboratory and provide the results quickly.
Hiro Clinic NIPT normally sends the results within 6 days after the blood sample is taken.
Is there any age limit for NIPT
(New Non-invasive Prenatal Testing?
The age limit for NIPT (New Non-invasive Prenatal Testing) has been removed.
Previously, accredited facilities had defined the target age group for NIPT (New Non-invasive Prenatal Testing)to be ’35 years or older as of the expected date of delivery’. This is thought to be due to the fact that the incidence of chromosomal abnormalities increases as the mother’s age increases.
However, this age limit was removed by guidelines promulgated by the Japan Medical Association on February 18, 2022. Now, regardless of age, you may consider taking the examination at your own request.
Who Should Consider Undergoing NIPT (New Non-invasive Prenatal Testing)?
According to the guidelines of the Japan Medical Association, pregnant women who may choose to undergo NIPT (New Non-invasive Prenatal Testing) are defined as those with the following conditions that increase the frequency of occurrence of the conditions covered by this test.
- Pregnant women of older age
- Pregnant women whose maternal serum marker tests suggest that the fetus may have a chromosome number abnormality
- Pregnant women with a prior history of carrying a child with a chromosomal numerical abnormality
- Pregnant women in whom either parent has a balanced Robertson translocation and which suggests the possibility that the fetus will have a Trisomy 13 and Trisomy 21
- Pregnant women whose fetal ultrasound examination suggests that the fetus may have a chromosome number abnormality
However, pregnant women with these conditions are not necessarily required to undergo NIPT (New Non-invasive Prenatal Testing), so their own wishes will be respected.
In addition, regardless of the frequency of occurrence of the applicable condition, for pregnant women who have concerns about numerical chromosomal abnormalities in the fetus that are not resolved even after appropriate genetic counseling, the decision of the individual regarding examination should be respected after providing sufficient information and support, and the test can be taken if the individual is willing, regardless of age or other conditions.
How much does the NIPT
(New Non-invasive Prenatal Testing) cost?
NIPT (New Non-invasive Prenatal Testing) is not covered by insurance, so the cost varies depending on the medical institution, but is generally between ¥80,000 and ¥200,000.
At facilities accredited for NIPT (New Non-invasive Prenatal Testing), the possibility with Trisomy 21 (Down syndrome), Trisomy 18 (Edwards syndrome), and Trisomy 13 (Patau syndrome) is tested for.
On the other hand, Nonaccredited facilities can often examine other chromosomes in addition to those, and often have a variety of plans available.
When was NIPT (New Non-invasive Prenatal Testing) introduced?
When was NIPT (New Non-invasive Prenatal Testing) introduced?
What kind of test is NIPT (New Non-invasive Prenatal Testing)? Let’s take a look at the history of NIPT.
Prior to the introduction of NIPT (New Non-invasive Prenatal Testing), prenatal diagnosis consisted of ultrasonography, chorionic villus testing, amniotic fluid testing, maternal serum marker testing (quattro test), and combined testing.
In 1997, it was discovered that DNA of fetal origin existed in the mother’s plasma, and research was conducted to develop a new type of prenatal diagnosis (NIPT), which can test for chromosomal abnormalities using only the mother’s blood.
When did NIPT (New Non-invasive Prenatal Testing)
begin in Japan?
In Japan, NIPT (New Non-invasive Prenatal Testing)was introduced in April 2013.
Difference Between NIPT (Non-invasive Prenatal Testing) and Conventional Prenatal Testing
So what are the differences between NIPT (Non-invasive Prenatal Testing) and conventional prenatal testing?
First of all, ultrasound examinations are performed by placing a probe on the abdomen as is done during a prenatal checkup, and the images are used to make a judgment. It is useful for detecting morphological abnormalities without the risk of miscarriage, but it is not very accurate in detecting chromosomal abnormalities.
In many cases, if an abnormality is found on ultrasound, it will be examined in detail by other tests.
Chorionic villus examination is a test in which villi are extracted from the placenta in early pregnancy to determine the shape and number of chromosomes. It is a definitive test and, if performed correctly, can confirm the presence or absence of chromosomal abnormalities, but because the villi are extracted, there is a 1% risk of miscarriage or stillbirth. The test can be performed between 11 and 14 weeks of pregnancy.
The amniotic fluid test is a test in which a sample of the mother’s amniotic fluid is collected and examined for fetal cells in it. It is a definitive test and, if performed correctly, can confirm the presence or absence of chromosomal abnormalities. However, since a needle is inserted into the abdomen to collect amniotic fluid, there is a possibility of infection and a 0.3% risk of miscarriage. The test can be performed at 15-16 weeks of pregnancy.
Maternal serum marker test (Quattro test) is a test that calculates the probability of chromosomal abnormalities in the fetus by measuring markers in the mother’s serum. The accuracy is about 70-80%, and the test can be performed at 15-17 weeks of pregnancy.
The combined test is a combination of ultrasound and blood sampling for serum marker testing. Ultrasound measures nuchal translucency (NT). The sensitivity is considered to be around 80-85% and the test is performed at 11-13 weeks.
NIPT (Non-invasive Prenatal Testing) is a test that examines DNA of fetal origin in the mother’s blood. Since only a blood sample is taken, there is no risk of miscarriage as with the chorionic villus and amniotic fluid tests. It is also very accurate, with a sensitivity of 99.9% and specificity of 99.90%. The test can be performed from the 10th week of pregnancy, earlier than other prenatal tests.
- Sensitivity – Probability of a positive test result among those who tested positive after delivery.
- Specificity – Probability of negative test results among those who tested negative after delivery
What is the probability of finding out the gender of the baby with NIPT (Non-invasive Prenatal Testing)?
We now know that NIPT (Non-invasive Prenatal Testing) is a risk-free test with a high probability of detecting chromosomal abnormalities. So what about gender, which is of concern to all pregnant women?
Since NIPT (Non-invasive Prenatal Testing) uses DNA derived from the fetus, the sex of the baby can be determined by examining the baby’s sex chromosomes.
However, at facilities accredited for NIPT (Non-invasive Prenatal Testing), you can only be tested for Trisomy 21 (Down syndrome), Trisomy 18 (Edwards syndrome), and Trisomy 13 (Patau syndrome). If you want to find out the sex/gender of your baby, consider a non-accredited facility that offers gender identification.
When can the gender be determined by
NIPT (Non-invasive Prenatal Testing)?
Usually, the gender/sex of the baby can be identified around the 5th month of pregnancy (from 16 weeks) by ultrasound examinations.
On the other hand, NIPT (Non-invasive Prenatal Testing) can be performed from 10 weeks of pregnancy. If the results are given early enough, it is possible to know the gender/sex of the baby at 11 weeks.
Is the Gender Identification by NIPT (Non-invasive Prenatal Testing) accurate?
NIPT (Non-invasive Prenatal Testing) uses DNA from the fetus to determine the gender with a fairly high accuracy rate of 99%.
Advantages of Knowing the Gender Before Birth
With NIPT (Non-invasive Prenatal Testing), it is possible to know the sex of the child earlier than with other conventional tests. The earlier we know the gender, the earlier we can start thinking about names and making preparations for after the birth. Above all, you can save time and ease uncertainty.
Things to Keep in Mind
When Undergoing Prenatal Testing
Prenatal testing is something that many people will want to take for peace of mind, expecting a negative result. However, in some cases, results turn positive, although the probability is low.
Please consider whether to take the test, assuming in advance what you will do if the results turn out to be positive.
Summary
In this article, information about prenatal testing has been provided. Conventional prenatal testing is inaccurate and risky, but by choosing NIPT (Non-invasive Prenatal Testing), you can avoid the disadvantages of conventional prenatal testing.
If you want to check for chromosomal abnormalities and know the gender/sex of your baby as soon as possible, please consider Hiro Clinic NIPT, which allows you to get the test results as soon as possible.
【References】
- Ethics Committee of the Japan Society of Obstetrics and Gynecology – 母体血を用いた出生前遺伝学的検査（NIPT）に関する指針
- The Japan Association of Medical Sciences Committee on Prenatal Testing Certification System – NIPT 等の出生前検査に関する情報提供及び 施設(医療機関・検査分析機関)認証の指針
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Article Editorial Supervisor
Dr Hiroshi Oka
NIPT specialist clinic, MD
Graduated from Keio University, School of Medicine
