Tehran University of Medical Sciences Journal of Family and Reproductive Health 1735-8949 14 2 2020 10 18 81 87 Shokoh Abotorabi Department of Obstetrics and Gynecology, School of Medicine, Qazvin University of Medical Science, Qazvin, Iran Niloufar Moeini Department of Biology, School of Basic Science, Qom Islamic Azad University, Qom, Iran Sahar Moghbelinejad Cellular and Molecular Research Centre, Qazvin University of Medical Sciences, Qazvin, Iran AND Khatam Pathobiology and Genetic Lab, Qazvin, Iran 2019 11 09 2020 07 29 Objective: The purpose of this study was comparison of association of three main first trimester screening factors with pregnancy outcomes among Iranian pregnant women. Materials and methods: This prospective study was done during 2017-2019 years in Qazvin, Iran. To do so, a total of 1500pregnant women in first trimester were enrolled. At the first step, Nuchal translucency (NT) was measured in 11-13 ± 5 week, then the serum pregnancy-associated plasma protein A (PAPP-A) and free-β-human chorionic gonadotropin (free-β-HCG) were measured in 12-14 weeks of gestation. Pregnant women were followed up until the end of pregnancy for the complications of pregnancy such as intra-uterine growth retardation (IUGR), intrauterine death (IUFD), different types of fetal loss and preterm labor. Results: The results showed that low levels of serum biomarkers had more association with pregnancy complications in comparison to high levels of them. Significant association of IUGR (P = 0.001), IUFD (P = 0.032) and pre-term labor (P = 0.002) was shown in women with low serum levels of PAPP-A in comparison to low serum levels of free-β-hCG. Significant high frequency of different types of fetal loss (IUFD, Abortion, Elective termination) was shown in fetuses with N ≥ 3 in comparison to low levels of serum biomarkers (P = 0.001). Conclusion: This study highlighted the importance of accurately interpreting the results of the first trimester of pregnancy screening which should be considered by primatologists for subsequent pregnancy care. https://jfrh.tums.ac.ir/index.php/jfrh/article/view/1254 https://jfrh.tums.ac.ir/index.php/jfrh/article/download/1254/519