Ovarian and reproductive hormone characteristics and risk of cycle cancellation in immediate versus postponed modified natural cycle frozen embryo transfer (mNC-FET) cycles

This study investigates whether ovarian and reproductive hormone characteristics, as well as the risk of cycle cancellation, differ between immediate and postponed modified natural cycle frozen embryo transfer (mNC-FET) cycles. The findings indicate significant differences in ovarian morphology, hormone levels, and follicular phase length between the two approaches, with a higher but not statistically significant cancellation rate in immediate cycles. These results raise concerns about the clinical feasibility of immediate FET treatment following ovarian stimulation.