Non-Invasive Prenatal Screening from a Genetic Counseling Prospective: Pre and Post-Genetic Counseling Regarding Rare Chromosomal Abnormalities and Incidental Finding

Abstract

Background: Arising in the late 1990s, when a promising role in prenatal diagnostics was first delineated for circulating fetal DNA, non-invasive prenatal tests (NIPTs) have been increasingly used with more frequency and popularity. These exams have been used as a prenatal screening tests for genetic diseases. Initially, they were developed for the investigation of the main fetal chromosomal aneuploidies, but lately they have also been used to rule out genomic microrearrangements and monogenic conditions. However, along with great opportunities and potential, the tests can show inconclusive or unexpected results. Several studies have shown that the current pre-test counseling is often insufficient, and more oriented at providing pieces of information about the identifiable diseases rather than providing extensive information on all possible scenarios which may affect both the fetus and the pregnant mother, especially in the case of an invasive test for the pregnant mother.

Methods and results: We have gathered from the literature on NIPT the main pitfalls, imperfections, and particular cases associated with this innovative diagnostic procedure.

Conclusions: In view of further improvements in the methods that can limit the inconclusive or unexpected results, this paper aims to reinforce the importance of more accurate pre-test counseling with comprehensive information about the above-mentioned questions, as well as ultrasound use and also the creation of an international consensus statement concerning these topics.

Keywords: circulating cell-free DNA (cfDNA); incidental findings; non-invasive prenatal testing (NIPT); prenatal screening; rare chromosomal abnormalities.