Abstract

Analysis of a pregnant woman’s blood sample allows NIPT (noninvasive prenatal testing) to detect the risk of foetal chromosomal disorders from the tenth week of pregnancy. In addition to the most common trisomies, NIPT also enables the detection of other changes in the foetal chromosome set, including microdeletions and duplications. In this article, we describe the early detection of three microdeletions in the first trimester, the size of which was 1-3 Mb. The findings are significant because, in the scientific literature, the detection limit for whole-genome NIPT technologies is considered to be 5 Mb. The rare nature of the findings (rare diseases) and the limited population of Estonia do not allow for calculating the sensitivity or specificity of detecting pathogenic microdeletions and duplications (PMD) in a short time window. Nevertheless, this article and other published works support the fact that the detection of PMD risk in early pregnancy allows for timely patient counselling, prenatal diagnostics, and informed family decisions.