VTE remains the most common cause of direct maternal deaths. POVT can occur after delivery causing severe complications. In pregnancy there is a progressive alteration in the balance between prothrombotic and anticoagulant factors, which both increase fibrin deposition and reduce fibrinolysis, resulting in a procoagulant state. Moreover, flow velocity in the lower limbs is reduced by approximately 50% by the third trimester and 50% of cases of VTE in pregnancy are associated with inherited or acquired thrombophilia. In ninety percent of the cases, the right ovarian vein is involved due to the incompetence of the valves. Enlarged pregnant uterus in twins may cause obstruction of IVC leading to vein stasis and its complications. Salomon and Dutizky[5, 7] wrote the first report of an association with twin delivery and the risk of POVT. The Author concluded that the size of the uterus during twin pregnancy resulted in compression of the ovarian vein. However all of their patients affected underwent artificial reproductive techniques in order to become pregnant, which was not the case of our patient. The most important risk factors are multiparity, puerperium, post-operative periods, infections, neoplasm, systemic lupus erythematosus and hypercoagulability states. Typical presentations include abdominal pain, pelvic or buttock pain in iliac DVT and neck pain when associated with Internal Jugular Vein thrombosis. Clinical presentation includes fever and pain to the right iliac fossa. Differential diagnostic with appendicitis, sepsis, ovarian torsion is mandatory and must be done in early stages to avoid massive thrombosis and PE, which can be fatal in some cases. Unusual presentation includes Budd-Chiari syndrome and cerebral vein thrombosis (CVT). In the study of Salomon and Dulitzky, only in 23% of the cases thrombophilia was discerned. Salomon et al. concluded that the risk for maternal POVT is increased by caesarean delivery of twins.
Early diagnosis may be done with compression ultrasonography (CUS) that has a sensitivity of 97-100% and a specificity of 98-99%, while contrast-enhanced CT and Magnetic Resonance Imaging (MRI) may confirm the diagnosis and quantify thrombosis extension and PE which occurs in 13% of cases. A thick-walled, enlarged ovarian vein with rim enhancement and central hypodensity are considered the main CT findings in POVT. If abdominal pain is present ultrasounds should be routinely performed during pregnancy to exclude ovarian thrombosis. Recent studies suggested that the risk of POVT increase after caesarean section. Broad-spectrum antibiotic treatment should be settled immediately, as should intravenous heparin or low molecular weight heparin (LMWH); once thrombolysis has begun, oral anticoagulants must be introduced and continued for 3 to 6 months. Despite the use of LMWH, DVT and embolism may develop. The optimum length of time for maintaining anticoagulation in these patients is unknown (5), therefore we may consider the possibility to continue therapy at least for 3 months with laboratory control.
Caval filter is recommended in extensive DVT and whenever discontinuation of anticoagulation might carry high risk of PE. Placement of VCF are particularly considered in case of a high bleeding risk, or other contraindications, precluding the use of therapeutic doses of Anticoagulation[1, 4]. There are no studies regarding the use of graduated elastic compression stockings (GCS) in pregnant women. However it is likely that stockings could be beneficial in this scenario. A meta-analysis in non-pregnant patients showed a reduction in risk of Post-thrombotic syndrome (PTS) and severe PTS in patients using GCS after diagnosis of thrombosis.
Hence the recommendation from the Royal College of Obstetricians and Gynaecologists is that GCS (knee-length with compression strength of 30–40 mm Hg) should be applied to help prevent PTS.
This leads to the recommendation that all women should be assessed for the risk factors of VTE in early pregnancy and that the assessment should be repeated if the woman is admitted to hospital or develops intercurrent problems. The assessment should be repeated anyway intrapartum or immediately postpartum.
In our reported case the complications were not prevented since the diagnosis and the therapy were performed too late. Maybe complications could have been avoided if early ultrasound was performed during pregnancy as soon as the patient was complaining of groin pain with no relief.
A better recognition of POVT syndromes leads to earlier diagnosis and more favorable clinical outcomes.