Non-Invasive Prenatal Testing (NIPT)

Non-Invasive Prenatal Test (NIPT) – BabySEQ

NIPT, also known as the Non-Invasive Prenatal Test, is a type of medical screening test performed during pregnancy to assess potential chromosomal abnormalities in the baby.

This test is performed using DNA obtained from the blood sample of the expectant mother, aiming to analyze the genetic information of the fetus. The term "non-invasive" is used because, unlike procedures such as amniocentesis, it does not require an invasive procedure through the abdomen, but instead is performed by simply collecting blood from the mother. This makes it a test that can be performed without causing stress for many expectant mothers.

What are the Goals 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 goal of the NIPT test is to identify potential chromosomal abnormalities during pregnancy. The main objectives of the NIPT test are:

• Trisomy Screening (Common Chromosomal Disorders):

  • Down Syndrome (Trisomy 21): NIPT is used to screen for Down syndrome, a condition seen in 1 in 800 births, with 90% detectable by ultrasound but 10% showing no signs. In Down syndrome, there are typically three copies of chromosome 21 (Trisomy 21).

  • Edwards Syndrome (Trisomy 18): Trisomy 18 occurs when the baby has three copies of chromosome 18. NIPT is also used to screen for Edwards syndrome.

  • Patau Syndrome (Trisomy 13): Patau syndrome occurs when the baby has three copies of chromosome 13. NIPT is an effective method for screening for Patau syndrome.

• Sex Chromosome Abnormalities:
  The NIPT test can also help identify abnormalities in the baby's sex chromosomes when suspected.

• Screening for Other Genetic Anomalies:
  In addition to common chromosomal disorders, NIPT provides information on numerical anomalies across all chromosomes. It also provides insights into certain conditions involving partial chromosome gains or losses that may not show any findings on ultrasound. Sometimes, these detected changes are present only in the placenta, not in the baby. In such cases, the test can still warn the obstetrician about potential pregnancy complications. Rare aneuploidies detected in the placenta (an extra or missing chromosome) are further investigated to confirm whether the baby has the same anomaly. For some chromosomal abnormalities, additional tests are required to determine whether the genetic material is inherited from both parents. These tests help diagnose rare conditions in the baby, such as Russell-Silver syndrome associated with uniparental disomy.

NIPT is an important tool for protecting maternal health and detecting a variety of conditions in the baby. However, every pregnancy is unique, and the choice of screening tests should be made under the guidance of a healthcare professional. It is important to consult a medical professional for more information on NIPT and other screening options.

When is the NIPT Test Performed?

The NIPT test is typically performed during a specific time period in pregnancy, depending on the week of gestation and the test's objectives:

• First Trimester (11-13 Weeks):
  NIPT can be performed as early as 11 to 13 weeks of pregnancy. Performing the test early is particularly effective for screening for Down syndrome and other trisomies.

• Second Trimester (14-24 Weeks):
  NIPT can also be performed in the second trimester, especially for families with increased risk detected by first-trimester screening or those unsure about amniocentesis. It provides an additional and more reliable screening option.

How is the NIPT Test Performed?

The NIPT test is performed by analyzing the baby's genetic material through a blood sample from the expectant mother. The general procedure includes:

1. Blood Sample Collection:
   A blood sample is collected from the mother's arm. The sample must be collected into a special tube provided by our center, and a vacutainer should be used. The sample should be transported quickly, as too much or too little blood flow during collection can affect the test quality. Samples arriving from abroad within 5-6 days are acceptable.

2. Isolation of Fetal DNA:
   The blood sample contains fetal DNA circulating in the mother's bloodstream. The lab uses specialized techniques to isolate the fetal DNA.

3. DNA Sequencing:
   The isolated fetal DNA is sequenced using high-precision techniques to ensure accurate data.

4. Analysis of Genetic Anomalies:
   The analysis identifies the fetal DNA and quantifies the amounts of all chromosomes, as well as any partial losses or gains.

5. Reporting of Results:
   A report is generated based on the data, reviewed by experienced medical professionals and geneticists in our center, and shared with the family and their physician with consent.

6. Counseling and Additional Testing:
   The clinical team evaluates the results. If an abnormality is detected, the obstetrician is informed. Further tests may be recommended, and our experts provide guidance to the family and the clinical team as needed. Pregnancy follow-up and anomaly screening are long and careful processes that require teamwork. We call this the "Next-Generation Pregnancy Monitoring Process."

Special Considerations in the NIPT Test

1. Early Pregnancy (10 Weeks):
   NIPT is generally not recommended before 10 weeks. In some cases, it can be performed at 9 weeks, but low fetal DNA levels may reduce test accuracy. If consulted, we recommend checking nuchal translucency before the test. Increased nuchal thickness may indicate genetic conditions, and in some cases, an invasive procedure may be required instead of NIPT.

2. Multiple Pregnancies (Twins, Triplets, etc.):
   In multiple pregnancies, NIPT must be interpreted carefully, as analyzing the genetic profile of each fetus is more complex.

3. Maternal Cancer or Other Conditions:
   If the mother has cancer, a bone marrow transplant, organ transplant, or certain chromosomal anomalies, the test results may be affected, and interpretation can be more challenging. Therefore, expectant mothers are asked to provide detailed information when taking the test.

4. Low Fetal DNA Levels:
   In some cases, maternal factors such as high body mass index (BMI) may result in low fetal DNA levels. Certain chromosomal conditions can also lead to low fetal DNA. If such a situation occurs, the family is informed, and a new sample may be needed.

What Does a Normal Test Result Mean?

A normal NIPT result indicates a low likelihood of a chromosomal disorder in the fetus. However, continued clinical follow-up is essential. If any ultrasound anomalies arise, the clinical team should be consulted, and genetic counseling may be provided. Even if invasive tests like amniocentesis or chorionic villus sampling return normal results, unexpected findings may still occur. Therefore, pregnancies should be monitored carefully by a multidisciplinary team, including obstetricians, geneticists, and other specialists as needed.

What Should Be Done If an Abnormality is Detected?

NIPT is a highly reliable screening test, but it is not diagnostic. If an abnormality is detected, confirmatory testing is required. Some detected changes may be maternal or placental in origin. If an abnormality is found, it is important to confirm whether it truly affects the fetus by planning additional tests. The family will be informed, and further action will be taken in consultation with the obstetrician and the clinical team.

Should We Be Worried If a Repeat Test is Requested?

Sometimes, a repeat test is needed due to technical issues or sample handling problems. This is not a cause for concern. Most of the time, the test can be successfully repeated. If the result is still inconclusive, please contact our center for guidance, and the next steps will be determined together with your obstetrician.

Remember: The NIPT test is a high-reliability screening test, but it does not replace diagnostic procedures such as amniocentesis or chorionic villus sampling. Our role is to guide you toward the most appropriate screening methods and inform you accordingly. Our goal is for every family to bring home a healthy baby. The mother and the fetus are both our patients, and our mission is to protect both while providing accurate information throughout this beautiful and exciting journey.