Background:The management of patients with recurrent miscarriage (RM) and antiphospholipid antibody syndrome (APS) includes prolonged treatment with heparin and aspirin,starting from the confirmation of pregnancy and continuing until 6 weeks after birth.This study was conducted to determine the relationship between changes in antiphospholipid antibody titers and clinical outcomes.The effect of a shortened treatment regimen was also evaluated.Methods:A prospective study of 123 patients with RM andAPS between March 2012 and May 2014 was conducted.Patients were pretreated with a low dose of prednisone plus aspirin before pregnancy,and heparin was added after conception.The levels of antiphospholipid antibodies and pregnancy outcomes were evaluated.Results:All patients were positive for anti-β2-glycoprotein 1 (anti-β2-GP 1) IgM.After prepregnancy treatment with low-dose prednisone plus aspirin,99 of 123 patients became pregnant,and 87 of those pregnancies resulted in successful live births,while 12 resulted in miscarriage,showing a success rate of 87.9％.In the live birth group,levels of anti-β2-GP1 were 56.8 ± 49.0 RU/ml before the pretreatment regimen,32.1 ± 26.0 RU/ml after 2 months ofpretreatment,and 24.1 ± 23.1 RU/ml during early pregnancy (P ＜ 0.05).In the miscarriage group,antiphospholipid antibody titers were 52.8 ± 30.7 RU/ml before pretreatment,38.5 ± 34.2 RU/ml after pretreatment,and 33.9 ± 24.7 RU/ml during early pregnancy;the decrease in antiphospholipid antibodies was lower in the miscarriage group than in the live birth group (P ＜ 0.05).Of the 24 infertile patients,the average antibody titer did not decline after pretreatment (P =0.802).Conclusions:Anti-β2-GP1 IgM was the predominant form of antibody in patients with RM and APS.The decreases in antiphospholipid antibody titers correlated with better pregnancy outcomes.The shorter treatment regimen was effective and economical.