Introduction
SECONDARY, MISCARRIAGE
Probiotics may be beneficial in multiple situations, including assisted reproduction technology. In women receiving assisted reproductive treatment, intrauterine lactobacilli dominance has been associated with higher rates of pregnancy achievementThe We designed this study to compare the biochemical pregnancy rate between women using intravaginal probiotic supplementation and those with standard treatment before embryo transfer (ET) in the frozen-thaw cycles. The primary outcome of the study was to compare the biochemical pregnancy rate between the study and control groups. The secondary outcomes were to compare the implantation rate, miscarriage rate, clinical and ongoing pregnancy rate, and live birth rate. 