Abstract Aim: To investigate the level of platelet volume and number precede Preterm Premature Rupture of Membrane (PPROM) development and to determine the predictive value of these markers for prediction of PPROM. Methods: A total of 979 pregnant women who received regular antenatal care until delivery were included. Participants were divided into 2 groups: Pregnant women with PPROM (n=140), and women without PPROM (n=839). Blood samples were collected during antenatal visits and/or during the period of inpatient hospital stay and changes in Mean Platelet Volume (MPV) and Platelet Count (PC) were compared between the two groups. Results: Compared with controls, women with PPROM had significantly increased levels of PC and significantly decreased levels of MPV in the first trimester (p<0.001). The area under the receiver operator curve was 0.9 for MPV and 0.67 for PC. The cut-off values of MPV <-7.9fL and PC >!270 X 103/µl predicted PPROM with a sensitivity of 69% and 70% and specificity of 58% and 50%, respectively. Conclusion: MPV can be used as a more efficient predictor for an early diagnosis of PPROM in the first trimester between 12 and 14 weeks' gestation than PC. However, further research combining other markers is needed to increase the efficiency of prediction.