Background: For further testing to rule out venous thromboembolism (VTE), pregnant women with high D-dimer levels are mandated to undergo further screening. Objective: Early detection of complicated pregnancy through evaluation of D-dimer level. Patients and methods: A total of 175 women were included in this case-control study and divided into 2 main groups: Group A "normal pregnancy": included 75 women who were subdivided into 3 equal groups (25 in each trimester) and group B "complicated pregnancy" that included 100 women all of them were in 3rd trimester of pregnancy who were subdivided into 4 equal groups (mild preeclampsia, severe preeclampsia, gestational diabetes mellitus and preterm rupture of membrane). D-dimer was assessed among all participants. Results: D-dimer (DD) and fibrinogen levels were significantly increased with increasing of gestational age. Fibrinogen and white blood cells levels were statistically significantly higher among diabetic, preterm rupture of membrane (PROM) and patients with mild preeclampsia, while D-dimer, platelet and hemoglobin levels were not significantly different when compared to normal pregnancy cases. D-dimer, fibrinogen and white blood cells in our study were significantly increased in cases of severe preeclampsia when compared to normal ones. So, D-dimer was considered a highly sensitive and specific biomarker in diagnosis of sever preeclampsia as D-dimer >100 ng/ml had 88% accuracy in prediction of sever preeclampsia. Conclusion: D-dimer was a highly sensitive and specific biomarker in diagnosis of severe preeclampsia only. D-dimer >100 ng/ml had 88% accuracy in prediction of sever preeclampsia.