Ovulation induction and endometrial steroid receptors

Area of Science:

• Reproductive Endocrinology
• Infertility Research
• Assisted Reproductive Technologies

Background:

• Endometrial receptivity is critical for successful implantation in assisted reproductive technologies (ART).
• Steroid hormone receptors in the endometrium play a key role in regulating receptivity.
• Ovulation induction protocols, commonly used in ART, involve supraphysiological hormone levels.

Purpose of the Study:

• To investigate the impact of ovulation induction on endometrial morphology and steroid receptor levels in infertile women undergoing ART.
• To correlate changes in endometrial steroid receptors with serum hormone concentrations and morphological assessments.

Main Methods:

• Studied 22 infertile women undergoing in-vitro fertilization or gamete intra-Fallopian transfer.
• Collected endometrial biopsies on the fourth day post-ovulation in spontaneous and treatment cycles.
• Assessed endometrial morphology via histology and measured estrogen and progesterone receptor levels using immunohistochemistry.

Main Results:

• Endometrial morphology remained 'in-phase' in most patients (20/22) in spontaneous cycles and all patients after ovulation induction.
• Ovulation induction led to a significant reduction in both progesterone and estrogen receptor levels in endometrial glands and stroma.
• These receptor reductions occurred despite supraphysiological steroid levels and were not associated with detectable morphological changes.

Conclusions:

• Ovulation induction in ART may lead to a downregulation of endometrial steroid receptors, potentially impacting receptivity.
• Morphological assessment alone may not fully capture the effects of ovulation induction on the endometrium.
• Further research is needed to understand the clinical implications of reduced endometrial steroid receptors on ART outcomes.