Deep vein thrombosis (DVT) is a common condition in which the approach to its diagnosis has evolved over the years. Currently, an algorithm strategy combining pre-test probability, D-Dimer testing and compression ultrasound imaging allows for safe and convenient investigation of suspected lower-extremity thrombosis. Patients with low pre-test probability and a negative D-Dimer test result can have proximal DVT excluded without the need for diagnostic imaging. The mainstay of treatment of DVT is anticoagulation therapy, whereas interventions such as thrombolysis and placement of inferior vena cava filters are reserved for special situations. The use of low-molecular-weight heparin (LMW) allows for outpatient management of most patients with DVT. The duration of anticoagulation therapy depends on whether the primary event was idiopathic or secondary to a transient risk factor. More research is required to optimally define the factors that predict an increased risk of recurrent DVT to determine which patients can benefit from extended anticoagulant therapy. DVT is also a serious problem in the antenatal and postpartum period of pregnancy. Thromboembolic complications are the leading cause of both maternal and fetal morbidity and mortality. The incidence of venous thromboembolism during normal pregnancy is six-fold higher than in the general female population of childbearing age. The treatment of DVT during pregnancy deserves special mention, since oral anticoagulation therapy is generally avoided during pregnancy because of the teratogenic effects in the first trimester and the risk of fetal intracranial bleeding in the third trimester. LMW heparin is the treatment of choice for DVT during pregnancy. If acute DVT occurs near term, interrupting anticoagulation therapy may be hazardous because of the risk of pulmonary embolism. In this situation, placement of a retrievable inferior vena cava filter must be considered. However, there is no consensus as to what the appropriate dose should be and whether anti-Xa levels need to be monitored. (J Turkish-German Gynecol Assoc 2011; 12: 168-75) Key words: Venous thrombosis, heparin, low-molecular-weight: heparin, anticoagulants, partial thromboplastin time, thromboembolism in pregnancy Received: 30 Junuary, 2011 Accepted: 25 May, 2011 Derin ven trombozları (DVT), teşhis yaklaşımlarının yıllar içinde büyük değişimler ve gelişmeler gösterdiği sık karşılaşılan bir durumdur. Son zamanlarda, pre-test probabilite, D-Dimer testi ve kompresyon ultrason görüntülemesini kombine eden bir algoritma stratejisi, alt ekstremite trombozlarından şüphelenilen olgularda hem güvenli hem de kullanışlı araştırma imkanı sağlamaktadır. Pre-test probabilitesi düşük, D-Dimer testi negatif olan hastalarda diagnostik görüntülemeye ihtiyaç olmadan, proksimal DVT dışlanabilir. DVT tedavisinin dayanak noktası antikoagü-lasyon tedavisidir, bununla birlikte tromboliz ve inferiyor vena cava filtreleri gibi girişimler özel durumlara mahsus tedavilerdir. Düşük moleküler ağırlıklı heparin kullanımı DVT'...