Randomized controlled study of pre-conception thromboprophylaxis among patients with recurrent spontaneous abortion related to antiphospholipid syndrome.

Objectives: To investigate the effects of pre-conception thromboprophylaxis among patients with recurrent spontaneous abortion and antiphospholipid syndrome.

Methods: A randomized placebo-controlled trial enrolled patients with a history of recurrent spontaneous abortions and antiphospholipid syndrome who attended an Egyptian center between January 2011 and June 2013. Using a computer-generated sequence, patients were randomly allocated to receive 41 mg enoxaparin subcutaneously plus 81 mg aspirin daily pre-conception, or to receive placebo pre-conception. All patients received enoxaparin and aspirin following identification of fetal heart pulsation. The primary outcomes were live-birth rate and clinical-pregnancy rate at 0-6 months, and at 6-12 months. Intention-to-treat analyses were performed. Clinicians, investigators, and data analysts were masked to the treatment assignments.

Results: The study enrolled 180 patients(90 in each group). No significant difference was observed between the intervention and control groups in the live-birth rate (67[74%] vs 59[66%]; P=0.25). At 0-6 months, the clinical-pregnancy rate was higher in the intervention group (50[56%]vs 30[33%], P=0.02). No significant difference between the intervention and control groups was observed in the clinical-pregnancy rate at 6-12 months (32[36%] vs 35[39%], P=0.52).

Conclusion: Among patients with recurrent spontaneous abortion and antiphospholipid syndrome, pre-conception enoxaparin increased the clinical-pregnancy rate at 0-6 months, but did not affect the clinical-pregnancy rate at 6-12 months or the live-birth rate. ClinicalTrials.gov: NCT01661439.