There are total 46 chromosomes in every baby. Half of the chromosomes are received from the maternal side and other half from the paternal side. However, in certain cases, when a baby is born, he/she might bear with an extra or a missing chromosome, which can result in a chromosomal condition in the baby. NIPT checks for chromosomal abnormalities which involve trisomy 21, trisomy 18, trisomy 13 and extra or missing copies of the X and Y chromosomes.
Non Invasive Prenatal Testing is a genetic screening test, performed through the mother’s blood sample. With an accuracy of more than 99% NIPT has become one of the most recommended screening tests by the healthcare providers. It gives an insight into genetic abnormalities from as early as the ten week of pregnancy.
This test does not bring any risk to your baby, as the name suggests it is a non-invasive process, which requires a simple blood draw and poses no risk of miscarriage. It is completely safe for the developing baby. Non Invasive Prenatal Test detect the presence of anomalies affecting chromosomes 21 (Downs syndrome), 18 (Edward syndrome) and 13 (Patau syndrome), also the most common anomalies affecting the chromosomes X and Y.
Earlier, tests for genetic abnormalities involved invasive procedures. It involved collecting a sample from inside the amniotic sac or from the placenta which was having a small risk of miscarriage. Therefore it was stressful to decide on whether or not to perform such a test. But now NIPT has totally changed the scenario making it easy for all the expecting parents.
NIPT is a non-invasive genetic test that checks for the baby’s DNA which is floating in the mother’s blood to detect the chromosomal abnormalities which are very common. By directly analyzing the baby’s DNA, Non Invasive Prenatal Testing results have been shown to be more accurate and have fewer abnormal results that are incorrect and fewer false negatives (i.e. normal results that are incorrect).There should be enough fetal cell free DNA in the mother’s blood to get any fetal chromosome abnormalities. The part of cell free DNA in mother’s blood is known as the fetal fraction. However, for a better result the fetal fraction must be at least 4%, which generally occurs around the tenth week of pregnancy. Low fetal fractions can lead to a false negative result or might be inefficient to even perform the test.
Who should be tested?
- Any women with advanced maternal age(>=35)
- High Risk on Markers test
- Abnormal ultrasound results
- History of a previous baby with Down’s syndrome
NIPT may also be considered as Chromosomal Analysis Test and its report provides with the information which shows whether the baby is at a low-risk or high-risk of having a genetic disorder.
High Risk– This result does not mean the fetus has a chromosomal abnormality, but, it points at a very high probability that the fetus may have that abnormality.
Low Risk– It indicates that the fetus is unlikely affected by one of the conditions.
