P-226: Non-Invasive Prenatal Screening for Fetal Chromosomal Anomalies in South of Iran

Background: Prenatal diagnosis for Fetal Chromosomal anomalies currently relies on assessment of risk followed by a combination of biochemical and nuchal translucency. Trisomy 21 is the most common trisomy that is associated with intellectual disability. Pregnant women who receive a prenatal diagnosis of trisomy 21 currently have the option of continuing or terminating their pregnancy, but no fetal treatment is available. Materials and Methods: A total of 157 women referred to social welfare organization participated in the first trimester screening for trisomy of chromosomes 13,18,21 based on biochemistry and nuchal translucency in 11-14 week of gestational age. Screen positive women elected for amniocentesis and karyotyping. Results: A total of 157 women participated in first trimester screening based on biochemistry and nuchal translucency. 61 women (38.8%) had age of more than 35 years. 125 women (61.6%) had consanguineous marriage, 52 women (25.8%) had at least one abortion. 45 women (22.3%) had positive screening result for trisomies. 31 women decided to do amniocentesis and cytogenetic tests that from them 6 fetus (19.3%) were affected (5 trisomy 21 and 1 trisomy 18) and referred for termination of pregnancy. Conclusion: First trimester screening is advantagenous for detecting pregnancies with increased risk of fetal chromosomal anomalies and reffering them for amniocentesis and cytogenetic evaluation to find affected pregnancies and terminate them on time.