Prior Thromboembolic Disease and Assisted Reproductive Therapy.

Assisted reproductive therapy (ART) increases the risk of venous thrombosis (VT) by 2- to 4-fold, whereas pregnancy increases the risk by 5- to 10-fold. Women with a history of VT undergoing ART are often suggested thromboprophylaxis. The literature is scarce and international guidelines are lacking. We made a review of the literature and base our suggestions primarily on expert opinions. We suggest women with a prior VT to use low-molecular-weight heparin as thromboprophylaxis starting from ovarian stimulation, throughout pregnancy, and 6 weeks postpartum. Assessment of VT risk should be done prior to ART. Adjustment of treatment to minimize the thrombotic risk, such as preventing ovarian hyperstimulation syndrome, single-embryo transfer, cryopreservation, and transfer of frozen embryos instead of fresh embryo in high-risk women, is suggested. Women with previous arterial thrombosis should continue aspirin during ART treatment, pregnancy, and postpartum.