Treatment of antiphospholipid antibody syndrome (APS) in pregnancy: a randomized pilot trial comparing low molecular weight heparin to unfractionated heparin. - Stephenson,M.D.; Ballem,P.J.; Tsang,P.; Purkiss,S.; Ensworth,S.T.; Houlihan,E.; Ensom,M.HH. (J Obstet Gynaecol Can, 2004)