In vitro evidences of heparin's effects on embryo implantation and trophoblast development.

Heparin seems to be effective in ameliorating pregnancy outcome in thrombophilic women with previous recurrent pregnancy loss, preeclampsia, intrauterine growth restriction and sudden fetal death. A prophylactic effect of heparin treatment has also been proposed in terms of prevention of adverse pregnancy outcomes recurrence in women with history of recurrent miscarriage, severe preeclampsia, placental abruption, low neonatal birth weight and intrauterine fetal death not related to thrombophilia, although literature in this field is quite controversial. The molecular mechanisms by which heparin might exert its potential therapeutic effects in human reproduction are still not fully understood. In this article we review the current knowledge in this research field, focusing on in vitro evidences of heparin's mechanisms of action in the processes of embryo implantation and trophoblast invasion.