background: Our aim was to study ways to improve IVF success rates in women with suspected endometrial receptivity defects. methods: We conducted a retrospective cohort study examining the effect of letrozole (aromatase inhibitor) on integrin expression as a marker of endometrial receptivity. We compared IVF outcomes in 97 infertile women who had undergone anb3 integrin assessment by immunohistochemistry in mid-luteal endometrial biopsies. Of 79 women undergoing standard IVF, 29 (36.7%) lacked normal integrin expression. Eighteen other women with low integrin were studied after receiving letrozole during early IVF stimulation. An independent set of anb3 integrin-negative patients (n ¼ 15) who had undergone repeat endometrial biopsy for integrin testing while taking letrozole were re-evaluated.results: Clinical pregnancy and delivery rates were higher in women with normal anb3 integrin expression compared with those who were integrin negative [20/50 (40%) versus 4/29 (13.8%); P ¼ 0.02 and 19/50 (38%) versus 2/29 (7%); P , 0.01, respectively]. In 18 women who received letrozole early in IVF, 11 conceived (61.1%; P , 0.001) compared with integrin-negative patients who did not receive letrozole. In integrin-negative women who were rebiopsied on letrozole, 66.7% reverted to normal integrin expression. Positive endometrial aromatase immunostaining using a polyclonal antibody was a common finding in infertile patients compared with controls.conclusions: Lack of endometrial anb3 integrin expression is associated with a poor prognosis for IVF that might be improved with letrozole co-treatment. Prospective studies are needed to confirm and extend these findings but the data suggest that aromatase expression may contribute to implantation failure in some women.

No abstract

No abstract

No abstract

No abstract