The Ratio of Prenasal Thickness (PT) to Nuchal Fold Thickness (NFT) in Fetal Screening Ultrasonography at Second Trimester of Pregnancy and the Relationship with Maternal Age, Gestational Age and Fetal Sex

Introduction: Regarding to the importance of the main role of ultrasonography in screening of chromosomal disorders, the present study was performed with aim to evaluate the relationship between NFT and PT in fetuses of second trimester of pregnancy; if these two ultrasonographic markers are correlated, PT can be used in fetuses in which NFT cannot be measured due to fetal position in the uterine. Methods: In this descriptive-analytical and cross-sectional study, 500 pregnant women at second trimester of pregnancy underwent routine ultrasound scan of anomalies. First, pregnancy ultrasound along with determination of gestational age and general pregnancy information, as well as scan of anomalies including all fetal organs were done and fetal sex, maternal age and gestational age were recorded. Data analysis was done using SPSS (version 22) and Statistica (version 10) statistical software. P