The potential role of heparin in assisted conception

BACKGROUND: Heparan sulphates play key roles in conception and early pregnancy events. The role of heparin, a structural analogue, and its application to assisted conception, is largely unknown. METHODS: Relevant studies were identified by searching PubMed 1966-November 2007 and Google Scholar without limitations. Sensitive search strategies were combined with relevant medical subject headings and text words. RESULTS: The similarities of heparin and heparan, the haemostatic changes induced by ovarian stimulation and the risk of thrombosis, the contribution of thrombophilia to pregnancy and infertility outcomes, early embryo-maternal dialogue and how these various aspects of assisted conception may be modified by heparin are reviewed. CONCLUSIONS: Heparin can alter the haemostatic response to controlled ovarian stimulation and modify the risk of thrombosis. It can also modulate many of the fundamental physiological processes required for blastocyst apposition, adherence and implantation and as well as trophoblast differentiation and invasion due to its similarities with heparan sulphates and has the potential to improve pregnancy rates and outcomes.