Aspirin appears to be as effective as enoxaparin for prevention of recurrent miscarriage in women who have unexplained reasons for pregnancy loss. A small study of 104 women with a history of at least 3 consecutive miscarriages showed equal efficacy with 100 mg daily of aspirin or 40 mg of enoxaparin twice daily. Women who had known possible causes of miscarriage such as hereditary clotting disorders, cardiovascular disease, thromboembolism, and abnormal thyroid function were excluded from the study. Live births occurred in 84% of women on aspirin and 82% of women on enoxaparin. The study was too small to detect a statistical difference. No placebo arm was included in the study. The authors defended this design by stating that women would not want to enroll in a study such as this knowing they might be randomized to placebo. A review of historical control patients showed a 60% live birth rate after 3 miscarriages and a 40% live birth rate after 4 miscarriages, indicating a possible benefit from the use of these medications to prevent pregnancy loss. Further study will be required to fully define the role of these medications.

Dr. Garrett is a clinical pharmacist practitioner at Cornerstone Health Care in High Point, NC.