Impacts of Cyclosporin A on clinical pregnancy outcomes of patients with a history of unexplained transfer failure: a retrospective cohort study

BACKGROUND: A rapid development in assisted reproductive technology (ART) has led to a surge in its popularity among target couples. However, elucidation on the molecular mechanism and effective solutions for a common problem posed by ART, namely transfer failure, is still lacking. The new therapeutic potential of cyclosporin A (CsA), a typical immunosuppressant widely used in the treatment of rejection after organ transplantation, in recurrent pregnancy loss (RPL) patients may inspire some novel transfer failure therapies in the future. To further explore the clinical effects of CsA, this study investigated whether its application can improve clinical pregnancy outcomes in patients with a history of unexplained transfer failure in frozen-thawed embryo transfer (FET) cycles. METHODS: Data from a retrospective cohort investigation (178 frozen-thawed embryo transfer cycles in 178 patients) were analysed using binary logistic regression to explore the relationship between CsA treatment and clinical pregnancy outcomes; the odds ratios (ORs) and 95 % confidence intervals (CIs) were calculated as a measure of relevancy. Implantation rate was the main outcome measure. RESULTS: There was no difference in the fine adjusted OR (95 % CI) of the implantation rate [1.251 (0.739–2.120)], clinical pregnancy rate [1.634 (0.772–3.458)], chemical pregnancy rate [1.402 (0.285–6.909)], take-home baby rate [0.872 (0.423–1.798)], multiple births rate [0.840 (0.197–3.590)], preterm birth [1.668 (0.377–7.373)], abnormal birth weight [1.834 (0.533–6.307)] or sex ratio [0.956 (0.339–2.698)] between the CsA-treated group and control group. No birth defects were observed in the present study. CONCLUSIONS: Although CsA does not affect infant characteristics, it has no beneficial effects on the clinical pregnancy outcomes in patients with a history of unexplained transfer failure in FET cycles.