ABSTRACT
Background: Failure in the endometrial receptivity may account for a significant number of infertility cases including unexplained infertility in women. Reduction in the endometrial estrogen receptor-alpha [ER-alpha] expression during implantation may be a critical event that coincides with the expression of specific genes and the formation of a receptive endometrium. The aim of the present study was to assess the expression of ER-alpha in the mid-secretory phase in the endometrium of women with unexplained infertility
Materials and Methods: This case-control study was carried out on randomly selected fertile [n=10] and infertile [n=16] women whose source of infertility remained unexplained. We evaluated the expression of ER-alpha and glycode-lin-A [GdA] through mRNA level measurement with real-time polymerase chain reaction [PCR] in the endometrium of fertile women and patients suffering from unexplained infertility and fertile women. Endometrial biopsies of each subject were collected during a single menstrual cycle 7 days after the peak of luteinizing hormone [LH+7]
Results: Endometrial expression level of ER-alpha was significantly [P<0.05] higher in the patients with unexplained infertility compared to the control. Significantly [P<0.05] lower levels of GdA expression were seen in women with unexplained infertility. A statistically non-significant negative correlation was observed between ER-alpha and GdA mRNA expression
Conclusion: Our findings demonstrate that reduction in the endometrial GdA expression is associated with elevated expression of ER-alpha in mid-luteal phase. Disruption in the endometrial ER-alpha expression, which leads to defects in uterine receptivity, may contribute to unexplained infertility