British Journal of Haematology , 2001, 115, 153±155 SHORT REPORT Internal jugular vein thrombosis after assisted conception therapy Roopen Arya, 1 Hassan A. Shehata, 2,3 Raj. K. Patel, 1 Satyajit Sahu, 1 Daghni Rajasingam, 3 Kevin F. Harrington, 4 Catherine Nelson-Piercy 2 and John H. Parsons 5 1 Department of Haematology, King's College Hospital, London, Departments of Obstetrics at 2 Guy's Hospital, 3 St Helier's Hospital and 4 Homerton Hospital, London, and 5 Assisted Conception Unit, King's College Hospital, London, UK Received 17 April 2001; accepted for publication 14 June 2001 Summary. Superovulation therapy during assisted con- ception may result in a hypercoagulable state. Five cases of upper extremity venous thrombosis were identified in women who conceived after ovarian stimulation for in vitro fertilization (IVF). They presented between 7 and 10 weeks' gestation with neck pain and swelling. Three had been treated for ovarian hyperstimulation syndrome and two had evidence of inherited thrombophilia. Four patients received thromboprophylaxis before presentation. Although thrombosis is an uncommon complication of IVF, patients should be counselled before treatment. Thrombophilia screening may be considered for `high-risk' patients, although current regimes for thromboprophylaxis remain suboptimal. Keywords: jugular vein thrombosis, ovarian hyperstimula- tion, in vitro fertilization, assisted conception, thrombophilia. The thrombotic risk associated with hormonal therapies such as the combined oral contraceptive pill and hormone replacement treatment is well established, as is the characterization of pregnancy as a hypercoagulable state. These two factors combine in women having assisted conception therapy, yet there is limited awareness of the increased risk of thrombosis in this situation. In vitro fertilization (IVF) involves the controlled pharmacological stimulation of ovarian follicles using gonadotrophin releasing hormone (GnRH) analogues and exogenous gonadotrophins, resulting in a marked increase in the number of developing ovarian follicles and ovarian enlargement. Two to 6% of IVF treatment cycles may be complicated by ovarian hyper- stimulation syndrome (Whelan & Vlahos, 2000). In 1±2% of IVF cases this may be severe, and is characterized by ovarian enlargement, ascites, pleural effusions, hypo- albuminaemia and reduction of intravascular volume. These changes are accompanied by hypercoagulability (Aune et al, 1991) and both arterial and venous thromboses have been reported (Baumann & Diedrich, 2000). Manage- ment of severe ovarian hyperstimulation syndrome (OHSS) consists of hospitalization for abdominal paracentesis and intravenous fluid and electrolyte administration. In most protocols, thromboprophylaxis takes the form of regular prophylactic unfractionated heparin (UFH) or low-molecular weight heparin (LMWH) during the period of hospitalization together with the use of graduated compression stockings. In the past year, we identified five cases of internal jugular vein thrombosis in women who conceived after ovarian stimulation for IVF in three London hospitals. This constitutes the largest reported series of such patients (Table I). They all presented with neck pain and swelling at 7±10 weeks' gestation, several weeks after ovarian stimula- tion. Duplex scanning revealed upper extremity deep vein thrombosis (DVT) in all cases, localized to the right in four and the left in one. One patient suffered a pulmonary embolism soon after presentation. In four cases, thrombosis occurred despite the use of thromboprophylaxis with LMWH or UFH (preparations and doses given in Table I). Four cases were treated with LMWH during the pregnancy and 6 weeks postpartum but two received intravenous UFH in the acute phase. In the postpartum period, patients were given the option of changing to warfarin but preferred to continue on LMWH. One patient received therapy with LMWH for only 3 weeks. Subsequently, she refused further anticoagulation and took low-dose aspirin for the rest of the pregnancy. In the postpartum period, she received LMWH prophylaxis for 6 weeks. Aged between 24 and 32 years, three patients were of Northern European and two of South Asian origin. All q 2001 Blackwell Science Ltd 153 Correspondence: Dr Roopen Arya, Department of Haematological Medicine, King's College Hospital, Denmark Hill, London SE5 9RS, UK. E-mail: roopen.arya@kcl.ac.uk