Clinical use of combined first-trimester screening test for aneuploidy at Saint Pauls Hospital Millennium Medical College: retrospective institutional study

Abstract

ABSTRACT BACKGROUND: Multiple studies show that combined first-trimester screening is effective to detect major fetal aneuploidies. In Ethiopia, these screening tests are practiced in some centres, mainly in centres with maternal-fetal medicine sub-specialist. However; there is no single study on the performance of this important prenatal screening tests in Ethiopia. OBJECTIVES: To describe clinical use of combined first trimester prenatal screening tests and clinical characteristics of cases with positive screening result at Saint Pauls Hospital Millennium Medical College, Ethiopia. METHODOLOGY: This retrospective study was conducted from July 2016 to July 2023 at SPHMMC. Data on nuchal translucency, maternal age, weight, gestational age provided by obstetrician. Determination of β-human Chorionic Gonadotropin (β-hCG) and pregnancy associated plasma protein A(PAPP-A) was done at LABCO advanced laboratory. Risk assessment was done with Snibe 2000 software by using maternal age, nuchal translucency, PAPP-A, β- hCG and other maternal characteristics. Genetic test for high risk cases was done at MRC-ET diagnostic laboratory. Statistical analysis was done using SPSS version 22, Fishers exact and Man Whitney U test done to see association between dependent and independent variables with p-value less than 0.05 considered statistically significant. Result: Overall high risk cases for aneuploidy are 24.8%. High risk cases who tested positive for aneuploidy have significant association with increased nuchal translucency, low PAPP-A values in MoM and modest association with pregestational diabetes. Conclusion: This study shows significant association of aneuploidy with increased nuchal translucency, low levels of pregnancy associated plasma protein A in MoM and presence of diabetes. Risk of having aneuploidy like trisomy 21 and 18 is not limited to women older than 35 years, which may necessitate the need for universal screening in the future. Key words: Aneuploidy, combined first trimester screening, multiples of median, nuchal translucency, PAPP-A, free β-hCG.