Abstract
Background: Pregnancy is a state of hypercoagulation which is likely an adaptive mechanism to maintain placental function during pregnancy and to prevent excessive bleeding in delivery but may increase the tendency of thromboembolism in predisposed pregnant females.

Aim and Objective: The aim of the study was to determine some hemostatic parameters in different trimesters of normal pregnant females and to compare them with hemostatic parameters of normal non-pregnant females.

Materials and Methods: This prospective pilot cross-sectional study included a total of 120 subjects. Thirty controls were matched with the study population which included 30 subjects of each trimester (1st, 2nd, and 3rd trimesters). The blood hemostatic parameters which were compared between the control and the study population were prothrombin time (PT), activated partial thromboplastin time (aPTT), platelet count (PLT), and fibrinogen (Fb). Results were expressed as means and standard deviations, statistical analysis was performed using Student’s t-test and analysis of variance test, SPSS software version 20. P < 0.05 was considered significant.

Results: Significant change in PT was seen in 3rd trimester as compared to non-pregnant controls although it decreased gradually from 1st to 3rd trimester. aPTT showed significant decrease in all three trimesters when compared with non-pregnant controls. PLT showed significant decrease only in 2nd and 3rd trimesters as compared to controls. Fb level showed significant increase in all trimesters as compared to normal controls.

Conclusion: Our study concludes that changes in coagulation system in normal pregnant Indian females are consistent with a continuing low-grade process of intravascular coagulation especially in the 3rd trimester of pregnancy. Therefore, all pregnant females, especially those predisposed for hypercoagulation state should undergo coagulation
studies during pregnancy.