NIPT Test (Noninvasive Prenatal Testing)

• The test is intended for use in pregnant women between 10-17 weeks of pregnancy and who are at high risk for the chromosomal aneuploidies. 
• NIPT is recommended for pregnant women to screen for chromosomal diseases that are brought on by an extra or missing copy of a chromosome (aneuploidy).
• NIPT is used to determine the risk for the foetus being born with certain genetic abnormalities such as:

1. Down syndrome (trisomy 21, caused by an extra chromosome 21)
2. Edwards syndrome (trisomy 18, caused by an extra chromosome 18)
3. Patau syndrome (trisomy 13, caused by an extra chromosome 13)
4. Extra or missing copies of the X chromosome and Y chromosome, the sex chromosomes)
5. Aneuploidies (missing (deleted) or copied (duplicated) sections of a chromosome)

• NIPT is recommended for all types of pregnancies.
• NIPT is offered to all women after at least 10 weeks of pregnancy.
• NIPT is recommended as the first line of screening for all pregnancies, irrespective of the risk. 
• NIPT is especially significant if the woman is above 30 years of age.

Patient Preparation: 12-14 hrs fasting required. NIPT is recommended at gestational age between 10 and 17 weeks. Sample collection is required to be done in special tube (streck tube) & by prior appointment. The patient is required to fill test requisition form (TRF) which include Clinician Stamp, Ultrasound Report (USG), Dual and Quadruple Marker Report, and Photo Identification Proof.

NIPT test measures foetal cell-free DNA (cfDNA) in the mother’s bloodstream to be able to identify foetal chromosomal or genetic abnormalities.

NIPT test requires a blood sample. A tourniquet (elastic) band is placed tightly on the upper arm. The patient is then asked to make a fist. This helps in the build-up of blood filling the veins. The skin is disinfected before needle insertion and the blood sample is collected in vacutainer.

NIPT test is performed on ION Genestudio S5 Plus NGS platform and involves isolation of cell free fetal DNA from maternal blood, generation of genomic DNA library, high throughput sequencing of extracted cell free fetal DNA and calculation of molecular mass of fetal DNA in chromosomes. Chromosomal aneuploidies can then be detected using bioinformatics analyses (Sage 12plex analytic program version v.1) where the detection rate and sensitivity are over 99%.

A "low risk" result indicates that there is often very little probability that the baby will have trisomy 21, trisomy 18, or trisomy 13. A trisomy 21, trisomy 18, or trisomy 13 result that is marked as "high risk" indicates that the infant is likely to have one of these chromosomal errors. If your NIPT result is "high risk," you should consulkt a genetic counsellor who can explain your results, offer assistance, go over your options, and set up additional testing as necessary.

To be able to detect foetal chromosome abnormalities, there must be sufficient foetal cfDNA in the mother's bloodstream. The foetal fraction is the percentage of cfDNA in maternal blood that originates from the placenta. The foetal percentage must normally be greater than 4%, which happens during the ninth week of pregnancy. Low foetal fractions may prevent the test from being run or result in a false negative. Low foetal fractions can be caused by foetal abnormalities, sampling mistakes, maternal obesity, and testing too early in the pregnancy.

• D0039 Maternal Screen-1st Trimester Dual Marker Test 
• D0041 Maternal Screen-2nd Trimester Triple Marker Test
• D0040 Maternal Screen-2nd Trimester Quadruple Marker Test