EP07.58: Prenatal detection of Down syndrome based on second and third trimester ultrasound scan

The aim of the study was to analyse incidence of Down Syndrome suspected on late trimester scans. All pregnant women who gave birth to a baby with confirmed karyotype of Down Syndrome were included and their prenatal medical records were analysed. Based on ultrasound reports and further recommendations for prenatal genetic testing, the cases were grouped in suspected and non-suspected for Down Syndrome. SPSS Version 22. Was utilised for statistical analysis. Continuous variables were expressed as Mean (minimum – maximum) for non-parametric variables. Categorical variables were expressed as frequencies (n) and percentage of occurrence (%). Out of 126 (0.2%) mothers who gave birth to Down Syndrome neonates, 80(63%) had at least one prenatal scan. 50 (63%) of them had one or more abnormal finding on prenatal second and/or third trimester scan. 27 (54%) among them had an isolated ultrasound finding such as: structural anomaly, soft marker, growth restriction, abnormal Doppler, or polyhydramnios. 23 (54%) pregnancies carried more than one abnormal ultrasound feature. 15/80 (19%) fetuses were suspected with Down Syndrome. 11/80 (14%) had non-invasive, cell-ff DNA and 1/80 (1%) invasive test that confirmed prenatal diagnosis of Down Syndrome. Late second and third trimester scan yield low suspicion of Down Syndrome. Although pregnancies with Down Syndrome are not considered an indication for termination of pregnancy among some countries and institutes, its early prenatal diagnosis through well established first trimester aneuploidy screening programs may positively contribute in patients' counselling and support as well as neonatal and future child care.