Abstract

AIM: Non -Invasive Prenatal Test is the testing for cell free fetal DNA from maternal blood during pregnancy for Trisomy 21, 18,13 and Monosomy 45XO. The aim of our study is to review our institution’s experience in the use of non-invasive prenatal test for aneuploidy screening
METHODS: It is a retrospective study of pregnant women who had undergone non-invasive prenatal test between January 2015 and December 2018 at Fernandez Hospital. A detailed Ultrasonogram is done as a mandatory prerequisite before NIPT to rule out major structural anomalies; pre and post- test counselling was done to all pregnant women who underwent non-invasive prenatal test
RESULTS: 322 women who had undergone non-invasive prenatal test were included in the study. 32% of the study population were of advanced maternal age. Low fetal fraction was seen in 2.1% of the study population. An abnormal non -invasive prenatal result (aneuploidy detected or inconclusive result) was reported in 36/322(11%).NIPT had a sensitivity of 100% and specificity of 99.6% in our study. Ever since NIPT has been introduced in our clinical practice the rate of invasive tests performed declined and the number of non-invasive prenatal test performed increased yearly
CONCLUSION: NIPT is an excellent method for screening for aneuploidy. There is an increasing uptake of NIPT and a decline in the rate of invasive tests performed. The occurrence of false positive results emphasizes that NIPT is a screening test and not to be considered as a replacement for diagnostic tests.

Key words: Aneuploidy screening, non-invasive prenatal test, invasive tests