Clinical utility of PregascreenTM reflex genetic testing for pre-natal screening in Indian population: A new diagnostic approach

Abstract

Prenatal screening with maternal biochemical dual and quadruple markers, along with reflex testing using karyotyping, and non-invasive prenatal testing via next-generation sequencing (NIPT-NGS) were evaluated to determine the clinical validity of Metropolis Pregascreen reflex testing approach among Indian women. Retro-prospective data of 51574 Indian women undergoing maternal marker screening from January 2021 to March 2022 were analysed at Metropolis Healthcare Limited, India. First and second-trimester prenatal screening were performed using Roche and Siemens platforms. Risk calculated using SSDW and PRISCA software, USG findings and biochemical values were incorporated. NIPT reflex testing was carried out using Thermo Ion torrent S5 NGS systems, while karyotyping on chronic villus sampling or amniocentesis. Total 51574 women opted for the combined biochemical markers test (dual and quadruple), 1394 cases (2.70%) and 50180 cases (97.28%) were screened as high-risk and low-risk, respectively. Of the total high-risk cases, 483 women (34.65%) opted for NIPT, while 25 (1.79%) opted for karyotyping reflex testing. Dual marker 92% and quadruple marker 94% of high risk cases were reclassified as low risk post NIPT, while dual marker 91% and quadruple marker 93% of high risk cases were reclassified as low risk post karyotyping. Possibility of ruling out false positive is almost equal with NIPT and karyotyping. Hence, invasive screening could be avoided as first line of investigation.Metropolis Pregascreen reflex testing with NIPT assisted in the delineation of actual high risk cases for accurate and safer diagnosis.