Objective: To determine the incidence and the type thromboembolic complications in patients undergoing in vitro fertilization (IVF). To evaluate their clinical course, the infl uence on reproductive outcomes, and the prevalence of thrombophilia in these women. Design: Retrospective clinical study. Setting: Assisted Reproduction Center, Department of Obstetrics and Gynecology, 1st Faculty of Medicine and General Faculty Hospital, Charles University, Prague. Methods: The data, refl ecting the diagnosis of thromboembolism (TE), were collected from all patients, who have undergone the IVF cycle in our clinic for the last 7 years. The following data were analyzed in these patients: medical history, type and course of TE, type and effect of ovarian stimulation, clinical pregnancy achievement, occurrence of ovarian hyperstimulation syndrome (OHSS), results of testing for thrombophilia, pregnancy course and outcome. Results: From 2748 IVF cycles 3 cases of TE were found (0.11%). In all cases the unilateral thrombosis of internal jugular vein associated with OHSS, manifesting in 1st trimester of pregnancy and not complicated with pulmonary embolism occurred. At least two thrombophilic markers have been detected in all these women. The clinical course of TE, as well as of the whole gestation was favorable. Prevalence of TE in patients with severe OHSS was 4.1% (2 women from 49). Conclusion: The incidence of thromboembolism in women undergoing IVF is low. It appears almost exclusively in association with OHSS and the typical fi nding is deep venous thrombosis in the neck area. In our opinion, while screening of thrombophilia in all patients from IVF program is not indicated, the routine testing of most common thrombophilic markers in pregnant women with OHSS could decrease the risk of these serious complications.

        Key words: IVF, OHSS, thromboembolism, thrombophilia