AbstractIntroduction: The present study aimed to assess whether changes in platelet indices, during pregnancy could be used as markers for prediction of development of hypertensive disorders of pregnancy. Methods: A total of 255 antenatal patients matching the inclusion and exclusion criteria was taken up for this study. Platelet count and its indices (MPV & PDW) were done at 10-12 weeks and repeated again at 28-30 weeks. Clinical manifestation of development of hypertensive disease and its relation with platelet indices in respective patients were analyzed. Results: Mean platelet count at 10-12 weeks was 2.53 lakhs in normotensives as compared to 2.21 lakhs in cases who developed HDP (p<0.05). Mean platelet volume (MPV) at 10-12 weeks was 9.74 fl in normotensives as compared to 10.81 fl in cases who developed HDP (p<0.05). Mean platelet distribution width (PDW) at 10-12 weeks was 11.89% in normotensives as compared to 14.15% in cases who developed HDP (p<0.05). Derangement of platelet indices was seen in 33 cases out of total 255 cases at 10-12 weeks. Out of these 33 cases, 6 (18.2%) developed HDP while out of the remaining 222 cases of normal platelet indices, 14 (6.3%) developed HDP. Conclusion: Platelet indices provide an effective tool to monitor HDP. The increase in PDW provides a tool in the early diagnostic assessment of HDP. Currently, the platelet count is only used as one of the criteria for the diagnosis of preeclampsia. However, assessing the PDW and MPV may be beneficial as an indicator of preeclampsia and eclampsia.