Expression of estrogen and progesterone receptors in the endometrium in women with impaired reproductive function with different functional activity of the corpus luteum of the ovary

Aim. To assess the expression of estrogen (ER) and progesterone receptors (PR) in the endometrium during the implantation "window" in women with impaired reproductive function with low (16.1<30 nmol/l) and high (P≥30 nmol/l)) functional activity of the corpus luteum of the ovary.

Materials and methods. A prospective single-center cohort comparative study. The main group included patients with infertility (n=93) and miscarriage (n=47) of unclear reason in the anamnesis, the control group – 16 healthy fertile women. In all cases, vacuum-aspiration endometrial biopsy was performed on the 6–8 days after ovulation with simultaneous collection of a peripheral blood sample to determine the levels of estradiol and progesterone. Endometrial samples were studied by histological and immunohistochemical (ER, PR expression) methods.

Results. Women of the main (1) and control (2) groups had an ovulatory menstrual cycle. The serum estradiol (E₂) level was 691.3±26.5 pmol/l (1) and 707.4±66.1 pmol/l (2); progesterone (P) – 46.1±1.8 nmol/l (2) and 39.1±4.9 nmol/l (2). Mid-secretory endometrium (results of histological examination) was determined in all healthy women (n=16) and in 46% (n=64) of the patients of the main group. All women in the control group had adequate hormone-receptor characteristics of the endometrium, in women in the main group – in 45% (n=63). Comparative analysis of the expression of ER, PR in the endometrium in patients with different functional activity of the corpus luteum of the ovary was carried out in the groups 1 and 2, in women with different reproductive dysfunctions in the anamnesis (without significant differences; p>0.05); subgroup analysis was performed in cohorts of women with normal (63 women in group 1 and 16 in group 2) and inadequate (77 patients in group 1) hormone-receptor status of the endometrium. There were no significant differences in the expression of ER, PR in the endometrium with low/high functional activity of the corpus luteum of the ovary with similar morphological characteristics of the endometrium (p>0.05). Correlation analysis did not reveal significant relationships between the level of P in the blood and indicators of endometrial expression ER, PR (p>0.05).

Conclusion. In the studied cohorts, the prognostic significance of the functional activity of the corpus luteum of the ovary for the adequate expression of estrogen and progesterone receptors has not been established. To clarify the presence/absence of endometrial dysfunction in women with a history of reproductive failures, a morphological examination of the endometrium of the middle secretion phase should be carried out.