NIPT (Non-Invasive Prenatal) Screening Test – BabySEQ

The NIPT test is a medical screening test used to assess possible chromosomal disorders in the baby during pregnancy.

What is Non-Invasive Prenatal Testing (NIPT)? – BabySEQ

The NIPT test is a type of medical test known as the “Non-Invasive Prenatal Test.” NIPT is a medical screening test used to evaluate possible “chromosomal disorders” in the baby during pregnancy.

This test is performed to examine the fetus’s genetic information using DNA obtained from the expectant mother’s blood sample. The term “non-invasive” is used because, unlike procedures such as amniocentesis, it is performed without an abdominal intervention—only by taking a blood sample from the mother. This makes it a test that can be performed for many pregnant women without causing undue anxiety.

What Are the Aims of the NIPT Test?

NIPT (Non-Invasive Prenatal Test) is a medical screening test that analyzes the baby’s genetic material through a blood sample from the expectant mother. The primary aim of NIPT is to identify potential chromosomal disorders during pregnancy. The main aims of the NIPT test are as follows:

1- Trisomy Screening (Common chromosomal disorders)

• Down Syndrome (Trisomy 21): NIPT is used to screen for Down syndrome, a condition observed in approximately 1 in 800 pregnancies. In about 90% of cases there are ultrasound findings, while in about 10% of pregnancies there may be no findings at all. In Down syndrome, there are typically three copies of chromosome 21 (Trisomy 21).
• Edwards Syndrome (Trisomy 18): Trisomy 18 refers to the presence of three copies of chromosome 18 in the baby. NIPT is also used to screen for Edwards syndrome.
• Patau Syndrome (Trisomy 13): Patau syndrome refers to the presence of three copies of chromosome 13 in the baby. The NIPT test is an effective method for screening for Patau syndrome as well.

2- Sex Chromosome Disorders

The NIPT test can also help identify suspected anomalies in the baby’s sex chromosomes.

3- Screening for Other Genetic Abnormalities

In addition to common chromosomes, the NIPT test can provide information about numerical abnormalities across all chromosomes. It can also provide information on conditions involving deletions or duplications in parts of chromosomes, which may sometimes show no findings on ultrasound. This is a very important topic. In some cases, a change detected by the test may not be present in the baby and may be confined only to the placenta. Even if it is not present in the baby, this may allow us to alert the obstetrician about certain complications that may occur during pregnancy follow-up. These rare aneuploidies detected in the placenta (an extra or missing chromosome) are first investigated by evaluating whether the same chromosomal change is present in the fetus. During this process, additional tests may be performed—often including obtaining genetic material from both the mother and the father—in order to identify certain abnormalities that cannot be detected with classical chromosome analyses. In this way, some rare genetic disorders that may affect the baby can be recognized early (such as disorders related to uniparental disomy, e.g., Russell–Silver syndrome).

The NIPT test is an important tool to help protect maternal health and detect many possible conditions in the baby. However, every pregnancy is unique, and which screening tests should be performed must be determined carefully under a doctor’s guidance. To learn more about NIPT and other medical screening options, it is important to contact a healthcare professional.

When Is the NIPT Test Performed?

The NIPT (Non-Invasive Prenatal Test) is typically performed within a specific time window during pregnancy. The most appropriate timing may vary depending on the gestational week and the aims of the test. Below are the time periods when NIPT is commonly performed:

• First Trimester (Weeks 11–13): NIPT can be performed as early as weeks 11 to 13 of pregnancy. Performing the test in this early period is highly effective for screening certain genetic abnormalities such as Down syndrome and other trisomies.
• Second Trimester (Weeks 14–24): NIPT can also be performed in the second trimester. In particular, it offers an additional and much more reliable screening option for families in whom increased risk is detected in the combined or triple test and who are unable to decide on amniocentesis.

How Is the NIPT Test Performed?

The NIPT (Non-Invasive Prenatal Test) is a screening test that analyzes the baby’s genetic material through a blood sample from the expectant mother. Below is the general procedure:

1. Blood Sample Collection: The first step is drawing a blood sample from the expectant mother’s arm. The collection step is critical for test reliability. The sample must be taken into a special tube provided by our center. Using a vacutainer is also recommended. If the sample is drawn too quickly or too slowly, more DNA from maternal cells may enter the serum and affect test performance. This procedure should be carried out under the described conditions by a laboratory technician or nurse. The sample should be delivered to our center without delay. For samples coming from abroad, delivery within 5–6 days is generally sufficient.
2. Isolation of Fetal DNA: The blood sample contains fetal DNA circulating in the mother’s bloodstream. In the laboratory, fetal DNA is isolated from the sample using specialized techniques.
3. DNA Sequencing: The isolated fetal DNA is analyzed using a high-sensitivity DNA sequencing technique to obtain clean and sufficient data. This enables detailed analysis of the baby’s genetic material.
4. Assessment of Genetic Abnormalities: The analysis is a crucial step. The fetal DNA is identified, and the quantities of all chromosomes are determined. In addition, deletions and duplications affecting parts of chromosomes can also be detected.
5. Reporting the Results: Based on the data obtained, a report is prepared. This report contains the screening results. It is first evaluated by experienced healthcare professionals and genetic specialists at our center. The report is then shared with the expectant mother and, with the family’s consent, forwarded to the attending clinician.
6. Counseling and Further Tests: The test results are evaluated by the clinician. If an abnormality is detected, the clinician is informed based on our center’s experience with the relevant finding. The obstetrician shares this with the expectant mother. If additional tests are needed, our specialists both inform the clinician and provide detailed counseling to the family. Pregnancy follow-up and anomaly screening is a long and careful process—absolutely a team effort. The obstetrician should also feel that they are not alone regarding genetic tests and their interpretation. We refer to this as a “new-generation pregnancy follow-up process.” It is not merely a laboratory test. The counseling provided afterward is as important as the test itself.

What Are Special Situations in NIPT Testing?

1. Early Pregnancy Period (10 Weeks): NIPT is not recommended before 10 weeks of pregnancy. It can be performed at 9 weeks if necessary; however, as the amount of fetal DNA decreases, interpretation difficulties may arise. When families consult our center, we recommend measuring nuchal translucency before the test when possible. Increased nuchal translucency can be a sign of many genetic disorders. In pregnancies with very high nuchal translucency, and after consultation with the attending obstetrician, an invasive diagnostic procedure may sometimes be preferred instead of this test. There are many genetic disorders other than chromosomal disorders that can also increase nuchal translucency (e.g., skeletal disorders, blood disorders, congenital heart diseases). In such cases, planning different tests using chorionic villus sampling or amniocentesis material may be necessary. For this reason, if expectant mothers with ultrasound anomalies contact our center, they are informed about which tests should be performed.
2. Multiple Pregnancy (Twins, Triplets, etc.): In multiple pregnancies (twin pregnancy, triplet pregnancy, etc.), NIPT results should be evaluated more carefully. In such cases, determining the genetic profile of each fetus can be more complex.
3. Maternal Cancer or Other Conditions: If the expectant mother has cancer, a history of bone marrow transplant, organ transplant, or certain chromosomal changes, test results may be affected and interpretation may be more difficult. For this reason, mothers with such medical history are asked to provide detailed information to our center at the time of sampling.
4. Insufficient Fetal DNA in Maternal Blood: The fetal DNA fraction can be low for various reasons. In mothers with very high body weight, fetal DNA may be very low. In some chromosomal disorders, fetal DNA may also be low. If such a situation occurs, the family is informed. Sometimes it may be necessary to collect a new sample and repeat the test.

What Does It Mean If the Test Result Is Normal?

NIPT is a screening test with high reliability. If the test result is normal, the likelihood of a chromosomal disorder in the fetus is very low. However, ongoing follow-up by your obstetrician is extremely valuable. If an ultrasound anomaly is detected during follow-up or an unexpected situation arises, contacting our center allows a plan to be made together with the clinician and genetic counseling to be provided. Even when this test is normal—and even when diagnostic tests such as amniocentesis or chorionic villus sampling are normal—unexpected findings may still develop during pregnancy follow-up. In such cases, careful consideration of genetic disorders is important, and follow-up should be planned by a team including the obstetrician, a geneticist, and other relevant specialists experienced in the specific anomaly.

If an Abnormality Is Detected in the Test Result, What Should Be Done?

It should be remembered that NIPT is a highly reliable screening test, but it can be misleading for various reasons. Therefore, before concluding that the fetus is affected, further tests should be planned according to the abnormality detected. Sometimes a maternal-origin change may lead to misinterpretation regarding the fetus. Sometimes a change may be present only in the placenta and detected by the test. For this reason, if a change is identified, additional tests may be needed to determine whether it truly affects the fetus. If you contact your obstetrician and our center, detailed information will be provided.

The Test Was Requested to Be Repeated—Should We Be Worried?

This analysis is performed using a blood sample from the expectant mother. If the quality of the fetal DNA obtained is not adequate, a repeat test may be requested. This can be due to technical reasons or issues related to sample transport. Please do not worry. In most cases, repeating the test yields a result and the report is delivered. However, if a result cannot be obtained even after repetition, we recommend contacting our center so that the next steps can be determined together with your attending obstetrician.

Remember: NIPT is a screening test with high reliability, but it does not replace diagnostic tests such as amniocentesis or chorionic villus sampling. Amniocentesis and chorionic tissue sampling are also widely used methods that enable diagnosis for many babies and, when performed properly, do not create a major risk for the baby. Our role is to identify the most appropriate screening approaches for you and to inform you accordingly. Everyone’s dream is to take home a healthy baby. Both the mother and the fetus are our patients. Protecting both and providing accurate information throughout this beautiful and exciting process is our responsibility.