Comparison of Doppler ultrasound indices of uterine artery and sub endometrial blood supply in frozen embryo transfer with and without repeated implantation failure: A cross-sectional study.

Uterine blood supply has been identified as a potential factor in implantation failure. This study aimed to investigate Doppler indices in the uterine artery, including vascular flow and resistance, as well as the amount of sub-endometrial blood supply in women with a history of repeated implantation failure (RIF) compared to the non-RIF group. This cross-sectional study was conducted with 139 women candidates for frozen embryo transfer in Yazd Reproductive Sciences Institute, Yazd, Iran from February to July 2023.