Effect of antiretroviral therapy on hemostasis in Brazilian pregnant women with HIV infection.

Clinical observation shows pregnant women under antiretroviral therapy present bleeding episodes at delivery, although this therapy promotes a decrease in fibrinolysis in nonpregnant patients, suggesting a prothrombotic state in the former. Since these drugs provoke hepatic disorders, they can cause bleeding disturbances. We investigated effects of antiretroviral therapy on hemostasis in pregnant women. Two groups were studied: pregnant women with HIV (n = 11), and (control) pregnant women without HIV (n = 7). Four blood samples were collected from each individual in both groups: one at the beginning of pregnancy before treatment, two during pregnancy and therapy, and one 6 weeks after delivery. Treatment was performed according to recommendations of the Brazilian Health Department for the evaluation of the prothrombin time, activated partial thromboplastin time, factors VII, X, and XII, fibrinogen concentration, protein C, protein S, tissue-type plasminogen activator (t-PA) antigen, plasminogen activator inhibitor-1, and fibrin degradation products (FbDPs). Statistical analysis demonstrated pregnancy caused increased factor VII (P = 0.0313), factor X (P = 0.0156) and factor XII (P = 0.0156) activity, fibrinogen concentration (P = 0.0156), t-PA (P = 0.0313), plasminogen activator inhibitor-1 (P = 0.0156) and FbDP levels (P = 0.0313). HIV infection caused increased factor XII (P = 0.0114), t-PA (P = 0.0346) and FbDPs (P = 0.0003), and decreased protein S levels (P = 0.0441). Antiretroviral therapy reduced the activated partial thromboplastin time (P = 0.0114) and protein S (P = 0.0012), and increased t-PA (P = 0. 0204) and FbDP levels (P = 0.0154). The results suggest a prothrombic state developing during pregnancy, maintenance of hemostatic equilibrium in HIV infection and occurrence of hyperfibrinolysis, not due to hepatotoxicity, during antiretroviral therapy, causing the clinically observed bleeding episodes.