Diagnostic approach to thrombocytopenia in pregnancy. ANA, antinuclear antibody; DAT, direct antiglobulin test; DIC, disseminated intravascular coagulation; HBV, hepatitis B virus; HCV, hepatitis C virus; LDH, lactate dehydrogenase; PEC, preeclampsia; PF4, platelet factor 4; TMA, thrombotic microangiopathy; TPO, thrombopoietin; TSH, thyroid stimulating agent; TTP/HUS, thrombotic thrombocytopenic purpura/hemolytic uremic syndrome.