Background: miscarriage, also known as a spontaneous loss of pregnancy before the fetus reaches viability. Objectives: the aim of this study is to evaluate the association between ultrasonographic findings and maternal serum biomarkers levels and prediction of pregnancy outcome in threatened miscarriage. Patients and Methods: a prospective observational study was conducted at Al-Zahraa University Hospital through the period from April 2018 to May 2019 involving 76 women in their first trimester threatened abortion. Results: there was a statistically significant difference between group 1 and group 2 regarding cancer antigen (CA) 125, β-hCG, progesterone, yolk sac diameter (YSD), fetal heart rate (FHR) and crown-rump length (CRL). The sensitivity, specificity, PPV and NPV of CA 125 at 37.2 IU/ml were 86.0, 84.3, 84.6 and 85.7, respectively, for β-hCG at 19447 IU/ml were 80.6, 78.0, 78.4 and 79.8, respectively, for progesterone at 12.3 ng/ml were 90.1, 88.0, 88.2 and 89.8, respectively, and for FHR at 122 b pm were 96.1, 94.1 respectively. Conclusion: combining of measurement of serum progesterone at a level of 12.3 ng/ml to FHR at 122 bpm represent noninvasive, early, fast and excellent predictor of pregnancy outcome in women with threatened abortion.