High expression of L-selectin ligand in secretory endometrium is associated with better endometrial receptivity and facilitates embryo implantation in human being.

PROBLEM: L-selectin ligand has displayed mediating adhesion at the maternal-fetal interface. Therefore, we investigated the impact of L-selectin ligand on establishing pregnancy in women undergoing in vitro fertilization and embryo transfer (IVF-ET).

METHOD OF STUDY: Endometrium between cycle days LH +6 to +9 was obtained from 56 Chinese women referred for IVF and tested for L-selectin ligand by immunohistochemistry and Western blot. The standard gonadotropin-releasing hormone agonist long protocol was used for ovarian stimulation.

RESULTS

L-selectin ligand was localized in the endometrial gland and luminal epithelial cells. Western blot analysis of endometrium identified four bands and levels of component 1, 2 and 4 were significantly higher in the pregnancy group than in the non-pregnancy group (P < 0.05). Clinical pregnancy and implantation rates were higher in patients with high level L-selectin ligand compared with those with low level (53.6%versus 25.0%, and 27.1%versus 12.1%, respectively, P < 0.05).

CONCLUSION

The presence of higher level L-selectin ligand was associated with a better pregnancy outcome.