Non-invasive Prenatal Test - A Pilot Pan-India Experience of an Indian Laboratory

Abstract

Background: Serum-based tests are considered to be a very affordable screening option for pregnant women. The non-invasive prenatal test (NIPT), among prenatal screening for chromosomal aneuploidies, has a sensitivity of >99%. The focus of this report is to present an overview of NIPT outcomes from samples tested in our national laboratory over a period of six months.Materials and Methods: NIPT was done by whole-genome shotgun sequencing, and a total of 513 pregnant women were tested in our laboratory. The samples were analyzed for reporting on the risk of trisomy 21, 18, and 13, as well as sex chromosome aneuploidies.Results: A total of 513 blood samples were received for NIPT testing, and 9.3% were canceled at the pre-analytical stage. The frequency of routine and IVF pregnancies was detected to be 83% and 12%, respectively. The frequency of high risk, including trisomy 21, trisomy 18, and sex chromosome aneuploidies, was detected to be at 3.0%, respectively. A total of 7% of cases that were reported as high risk by serum screening were detected to be low risk by NIPT.Conclusion: NIPT is an efficient aneuploidy screening tool, as it studies fetal DNA, and our analysis indicates that it can be beneficial in screening for fetal chromosomal risk with high sensitivity to identify cases that need confirmatory tests.

Keywords: Cell free DNA; Next-Generation Sequencing; Non-Invasive Prenatal Testing; Pregnancy; Screening