Effect of Enoxaparin on Live Birth Rate in Patients with Unexplained Recurrent Pregnancy Loss: A Randomized Clinical Trial

Background & Objective: The effectiveness of aspirin and heparin in improving live birth rates in unexplained recurrent pregnancy loss remains uncertain, and further research is needed on using low molecular weight heparins (LMWH). This study was conducted with aim to assess the impact of enoxaparin, an LMWH, and its outcomes in women with URPL. Materials & Methods: This single-blinded randomized clinical trial study was performed on 80 women with URPL and no history of thrombophilia. The participants were referred to the Infertility Clinic at Imam Reza Hospital (Milad Center) between March 2018 and February 2019. At the sixth week of gestation, the participants were assigned randomly to two groups (n=40 in each group). The treatment group received a daily subcutaneous injection of 40 mg of enoxaparin, while the control group received routine pregnancy care. Maternal and neonatal demographic data, pregnancy outcomes, complications, and live birth rates were recorded and subsequently compared between the two groups. Results: There was no significant difference between the two groups in previous pregnancies or miscarriages, and the live birth rate was about 85% in both groups. The occurrence of pregnancy complications was significantly higher in the treatment group compared to the control group (38.2% vs. 5.7%; P=0.021). Conclusion: Treatment with enoxaparin in women with unexplained recurrent pregnancy loss and no history of thrombophilia did not improve the pregnancy outcome nor decrease pregnancy complications.