Recurrent miscarriage and later
pregnancy complications are in some cases associated with placental
thrombosis and
infarction. The aim of this study was to assess the value of low dose
aspirin (75 mg daily) in improving the subsequent livebirth rate amongst women with either unexplained recurrent early
miscarriage (<13 weeks gestation; n = 805) or unexplained late pregnancy loss (n = 250). Amongst women with recurrent early
miscarriages, there was no significant difference in the livebirth rate between those who took
aspirin (251/367; 68.4%) compared with those who did not take
aspirin [278/438; 63.5%; odds ratio (OR) 1.24; 95% confidence interval (CI) 0.93-1.67]. This relationship was independent of the number of previous early
miscarriages. In contrast, women with a previous late
miscarriage who took
aspirin had a significantly higher livebirth rate (122/189; 64.6%) compared with those who did not take
aspirin (30/61; 49.2%: OR 1.88; 95% CI 1.04-3.37). The empirical use of low dose
aspirin amongst women with unexplained recurrent early
miscarriage is not justified. We are currently investigating the role of incremental doses of
aspirin in the treatment of women both with early
miscarriages associated with thrombophilic abnormalities and in those with late pregnancy losses.