Internal jugular vein thrombosis: a late complication of ovarian hyperstimulation syndrome despite mini-dose heparin prophylaxis.

Thromboembolic events are serious but rare complications following ovarian stimulation for in-vitro fertilization (IVF). We report a case of severe ovarian hyperstimulation syndrome (OHSS), presenting in a second IVF cycle with a late complication of right internal jugular vein thrombosis despite mini-dose heparin prophylaxis. Thrombosis and thromboembolism as late complications of OHSS have been reported by others but not after prophylactic heparinization. The patient was successfully treated with heparin and the twin pregnancy is ongoing. In pregnant patients with severe OHSS consideration should be given to treatment with low dose heparin throughout the first trimester to prevent the serious complications of thrombosis and thromboembolism.