Low dose aspirin rescues subsequent pregnancies of the patients with two consecutive miscarriages associated with antiphospholipid antibodies and/or hypercoagulability

Abstract

Antiphospholipid antibodies (APA) and/or hypercoagulability have been suggested to be one of the causes of recurrent pregnancy losses. Although anticoagulant agents such as low dose aspirin (LDA) have been used to treat recurrent pregnancy losses, their indications and effects have not been well evaluated. The present study was conducted to determine if LDA alone is effective to maintain pregnancy in the patients with recurrent pregnancy losses (RPL) associated with positive antiphospholipid antibodies (APA) and/or hypercoagulability. Retrospective analysis at private setting infertility clinic. Miscarriage rates after LDA treatment were compared between the patients with two consecutive pregnancy losses and three or more. Fifty one patients with more than two miscarriages (42 patients with two and 9 patients with 3 or more miscarriages) associated with positive APA (anticardiolipin antibodies, antiphosphatidylethanolamine antibodies, antiphosphatidylserine antibodies, lupus anticoagulant) and/or hypercoagulability detected by platelet aggregation test (PAT) from January 2005 through March 2007 were used to analyze. All patients received LDA (aspirin 81 mg/day) started from the day of ovulation or embryo transfer throughout pregnancy. The pregnancy outcomes were compared among each pathogenesis and also between the two groups (2 and 3 or more miscarriages). Seven (13.7%) out of 51 pregnant patients miscarried under LDA in subsequent pregnancies. The miscarriage rates with APA(+)PAT(+), APA(+)PAT(−) and APA(−)PAT(+) were 16.7% (2/12), 20.0% (1/5) and 11.8% (4/34), respectively and no significant differences each other. Ninety two point nine percent of the patients with two consecutive miscarriages (39/42) maintained their subsequent pregnancies under LDA, but only 55.6% (5/9) of the patients with three or more maintained with the same treatment. LDA did not show any differences of subsequent pregnancy outcome in the patients with various combinations of positive APA and PAT. However, LDA was significantly effective to the patients with two consecutive miscarriages, but not to the patients with three or more. The cause of recurrent pregnancy losses more than three times may involve some more factors other than APA and PAT and they may need some more treatments such as heparin and immunological therapy in addition to LDA. The present study suggests the efficacy of LDA and its limitations on recurrent pregnancy losses.