Prenatal serum screening - a summary of our experience with high risk reporting

Abstract

Objective The spectrum of pregnancy tests for screening of chromosomal disorders in the unborn child includes maternal serum testing through double, triple and quadruple marker as well as the emerging cell free fetal DNA analysis based noninvasive prenatal test. The aim of this short communication is to summarize our finding’s pertaining to high risk serum screening cases with reference to clinical indications and history. Methods Data of cases reported high-risk by serum screening including a total of 3368 women with median age of 32 years was included. Serum testing was done in the laboratory using the technology of Chemiluminescence micro particle two-step immunoassay for sensitive quantification of hormones routinely tested for in the double, triple and quadruple marker. Risk estimation using values of hormone levels and the resulting MoM was done using the PRISCA 5.0.2.37. Results A total of 16,608 samples were tested for serum screening in the study period and specific high risk analysis detected a total of 20% reported as high risk. Trisomy 21 was detected to be the most common finding at 86% followed by neural tube defects at 9%. Advanced maternal age (≥35 years) accounted for a total of 34% of the reported high risk cases. Conclusion The gap between absence of a nation-wide screening mandate, and guidelines for agencies involved in prenatal screening tests can be reduced with studies which focus on trends in recommendation and developing an understanding of the clinical backdrop leading to high risk screening results.