A Meta-analysis of Low-Molecular Weight Heparin to Prevent Pregnancy Loss in Women with Inherited Thrombophilia - WCRPL2017 – 2nd World Congress on Recurrent Pregnancy Loss, 19-22, January 2017, Cannes, France

Risto Kaaja ¹ Leslie Skeith ² Marc Carrier ² Ida Martinelli ³ David Petroff ⁴ Ekkehard Schleussner ⁵ Carl A Laskin ⁶ Marc A Rodger ²

¹Internal Medicine, University of Turku, Turku University Hospital, Finland
²Department of Medicine, University of Ottawa and the Ottawa Hospital, Canada
³A. Bianchi Bonomi Hemophilia and Thrombosis Center, Fondazione Istituto di Ricovero e Cura a Carattere, Italy
⁴Clinical Trial Center, University of Leipzig, Germany
⁵Obstetrics and Gynecology, Friedrich Schiller University Hospital, Germany
⁶Medicine and Obstetrics and Gynecology, University of Toronto, Canada

Background: Inherited and acquired thrombophilias have been evaluated as a potential cause of pregnancy loss, given the importance of adequate uteroplacental circulation on fetal development and survival. The role of Low-Molecular-Weight Heparin (LMWH) in women with an inherited thrombophilia and prior late or recurrent early pregnancy loss is not well established.

Objective: We sought to determine whether the use of prophylactic-dose LMWH (with or without aspirin) reduced the risk of pregnancy loss when compared with no LMWH (with or without aspirin).

Methods: We performed a meta-analysis of randomized controlled trials comparing LMWH vs no LMWH in women with inherited thrombophilia and prior late (≥10 weeks) or recurrent early (< 10 weeks) pregnancy loss.

Results: Eight trials and 483 patients met our inclusion criteria. There was no significant difference in livebirth rates with the use of LMWH compared with no LMWH (relative risk, 0.81; 95% confidence interval, 0.55-1.19; P = .28)(Figure A-B).

Conclusion: We found no difference in preventing future pregnancy loss with LMWH when compared with no LMWH in women with inherited thrombophilia and prior late or recurrent early pregnancy loss. Further research evaluating LMWH prophylaxis in women with thrombophilia and recurrent early pregnancy loss is still needed.

Figure*: Forest plot of the relative risk of pregnancy loss comparing LMWH vs no LMWH. (A) All trials are included. (B) Multicenter trials only are included.

*Ref: Leslie Skeith, Marc Carrier, Risto Kaaja, Ida Martinelli, David Petroff, Ekkehard Schleußner, Carl A. Laskin, Marc A. Rodger. A meta-analysis of low-molecular-weight heparin to prevent pregnancy loss in women with inherited thrombophilia Blood 2016 127:1650-1655.