Enhancing predictions of embryo implantation in thin endometrium: a comparative analysis of endometrial thickness in frozen versus fresh IVF cycles.

This study investigated whether the difference between endometrial thickness in the frozen embryo transfer (FET) cycle and the preceding fresh stimulated cycle predicts clinical pregnancy in women with thin endometrium. A retrospective analysis of 335 cycles in 227 women (age < 43) with endometrium < 8 mm in the FET cycle was conducted. Endometrial thickness was assessed using the ratio (ET) and absolute difference (ET) between the maximal endometrial thickness measured during the stimulated IVF cycle and that measured in the FET cycle.