SCIENTISTS ESTIMATED THE FUNCTIONALITY OF CARRYING OUT CHROMOSOMIC MICROMATRIC ANALYSIS IN MUCH DEVIATIONS IN THE SECOND TRIMESTER

When in the second trimester soft markers are detected by ultrasound (USM), questions of additional prenatal diagnosis arise. With the development of technology, various methods have appeared in the arsenal of doctors: non-invasive prenatal testing (NIPT) and invasive testing using karyotyping or chromosomal microarray analysis (CMA). Compared to invasive testing, NIPT using fetal extracellular DNA (cfDNA) from maternal plasma is safer and more acceptable for women. In contrast, invasive prenatal testing is done with chorionic villus sampling, amniocentesis, or cord blood sampling, which are associated with an increased risk of miscarriage and other side effects.

It is reported that mild ultrasound markers of chromosomal abnormalities are detected in about 5.9% of fetuses during the second trimester ultrasound, and because of this, the frequency of invasive tests increases by about 24-61 times. However, since USM is also present in a significant number of healthy fetuses, the question arises about the need for invasive diagnostic tests, given that today non-invasive prenatal tests (NIPT) are available to patients.

A new study showed that CMA has a significantly higher diagnostic value compared to NIPT (4.9%) and karyotyping (3.2%) in fetuses with mild ventriculomegaly (a pathology characterized by an increase in the size of the ventricles of the brain). However, for other USMs, both the authors' own research and meta-analysis have shown that performing HMA may be excessive.