Why do platelet counts increase at day 7-14 after major surgery?

Hemodilution and platelet consumption cause reduction in platelet count in early days post op (typically within 4 days of surgery), which leads to increased levels of thrombopoietin. The thrombopoietin response to acute thrombocytopenia takes 3 to 4 days to increase platelet production by bone marrow megakaryocytes, and results in a physiological “overshoot” in the platelet count. Postoperative platelet counts peak at two- to threefold the patient’s preoperative platelet count at approximately postoperative day 14, before gradually returning to the patient’s baseline value over the next 14 days. Learn more here.