El non-invasive prenatal test It is a test with which be able to detect chromosomal alterations in fetal DNA through maternal blood. Offers 99% reliability and It does not pose a risk to the mother or the fetus, being able to perform from the 10th week of gestation.
Through a simple extraction of blood from the mother, free DNA circulating in maternal plasma can be detected. Thus, through sequencing technology and advanced bioinformatic analysis, allows to know the sex of the baby and detect possible chromosomal abnormalities such as trisomy 21 (Down syndrome), trisomy 13 (Patau syndrome), trisomy 18 (associated with Edwards syndrome) and aneuploidies associated with the pair of sex chromosomes.
When to do the non-invasive prenatal test?
One of the great advantages of the non-invasive prenatal test is that it can be performed between weeks 9 and 10 of pregnancy. At that time, it should be the gynecology specialist who recommends the performance of the test and the optimal time for each patient, according to their history and circumstances of pregnancy.
In addition, as it is a test that does not affect either the mother or the fetus, it can be of great help to any woman who is expecting a baby, regardless of whether it is a single or multiple fetus. However, it is a test especially recommended for women whose maternal age is 35 years or older, since, the older the mother, the more risk the baby has of suffering from a genetic problem. It is also highly recommended if an ultrasound shows suspicion of genetic problems in the fetus, if the mother has already suffered chromosomal alterations in other pregnancies or if the mother already has genetic alterations that may affect the fetus.
How to interpret the results of a non-invasive prenatal test?
The non-invasive prenatal test allows screening and detection of possible fetal chromosomal abnormalities during pregnancy. It is a minimally invasive test with which to ensure that there is no type of chromosomal abnormality, but how to interpret the data from this prenatal test?
Once the test has been performed, results are usually in 7-10 days. It is then that conclusions can be drawn based on the data obtained. Keep in mind that the test results are numerical and the result will be based on a percentage:
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- Low risk or negative: when the test is negative or low risk, it means that there is hardly any probability of chromosomal alterations.
- High risk or positive: If the test is positive, it will be necessary to carry out other diagnostic tests with which to confirm the chromosomal alteration with certainty.
- Inconclusive: on few occasions the non-invasive prenatal test is inconclusive. In case this happens, it is advisable to repeat the test some time later.