Prospective, sequential, longitudinal study of coagulation changes during pregnancy in Chinese women

Abstract Objective To investigate changes and establish reference values for coagulation variables during normal pregnancy and after delivery in Chinese women. Methods A prospective, sequential, longitudinal study with strict inclusion and exclusion criteria was performed with 232 Chinese women. Results Prothrombin time, international normalized ratio, activated partial thromboplastin time, and activated partial thromboplastin time ratio were shorter, and platelet count decreased gradually during pregnancy, with no change in mean platelet volume; conversely, plasma concentration of both fibrinogen and fibrin/fibrinogen degradation product increased. All these variables were normalized during the postpartum. Reference values by gestational week were established for platelet count, fibrinogen concentration, and fibrin/fibrinogen degradation product concentration. Conclusions These reference values may be used in the health assessment of pregnant women with a similar socioeconomic and ethnic background.