This study was performed at kosti teaching hospital (Sudan). The aim of the study was to investigate the changes that occur in the coagulation parameters in pregnant women, which include estimation of prothrombin time, platelet count and international normalization ratio (INR). Hundred pregnant and hundred non pregnant women were randomly chosen and individually filled informed consent. The ages of the test group were ranging from 21-30 years, whereas the ages of the control group were ranging from16 to 35 years. Blood samples were taken from each woman. The prothrombin time, international normalization ratio (INR), and platelet count were determined using fully automated hematology analyzer and coatron M2. The obtained results were statistically analyzed using SPSS program. For the pregnants group, the analysis showed a mean prothrombin time of 17 sec, international normalized ratio of 1.4sec, mean international normalized ratio of 1.4sec, mean Platelet count of 165x10³cmm, mean platelet volume (MPV) mean of 8.7fl, and platelet distribution width 15.7. In control group the analysis showed mean prothrombin time of 15.1sec, mean international normalized ratio of 1.3sec, mean Platelet count 286cmm, mean (MPV) 10.3fl, and mean platelet distribution width of 19.6fl. It was found that, prothrombin time is prolonged especially in the third trimester and the Platelet count was significantly reduced in the pregnant group. The mean platelet volume and platelet distribution width were found to be normal in the two groups.