The risk of thromboembolism in relation to in vitro fertilization

Abstract

Objective: Summary of available literature concerning recommendation of antithrombotic prophylaxis in the infertility treatment by in vitro fertilization (IVF) and in pregnancies after IVF.

Design: Review article.

Settings: Department of Obstetrics and Gynecology, University Hospital Olomouc, Faculty of Medicine and Dentistry, Palacký University Olomouc; Institute of Medical Genetics, University Hospital Olomouc, Faculty of Medicine and Dentistry, Palacký University Olomouc.

Methods: Analysis of literary sources and databases Medline, Web of Science, Scholar Google, 2010-2018.

Conclusion: The incidence of thromboembolism in the first trimester of pregnancy after IVF is 0.2% e. g. 10-times higher compared to normal pregnant population. Pregnancies after IVF are complicated in 6-7% by ovarian hyperstimulation syndrome (OHSS), they then have the risk of venous thromboembolism (VTE) 1.7% in the first trimester, what is 100-times higher as compared to the general population. Women after IVF without OHSS have a 5-times higher risk of VTE compared to the general population. To lower the risk of thromboembolism during treatment, use of low dose gonadotrophin (mild) stimulation protocols, prioritization of antagonistic stimulation protocols, avoidance of OHSS using GnRH agonists instead of hCG, cryo embryotransfer in natural cycles, reduction of incidence of multiple pregnancy by single embryo transfer, use of prophylactic and therapeutic low molecular weight heparin (LMWH) is recommended. These strategies can reduce the risk of thromboembolism. The LMWH application is suitable in pregnant women in the first trimester of pregnancy after IVF where OHSS was present.

Keywords: assisted reproduction; in vitro fertilization; ovarian hyperstimulation syndrome; thromboembolism.