P-517 The effects of various female infertility factors on endometrial receptivity
Authors: Chen M  J , Yang P  E , Yi Y  C , Kung H  F , Chang J  C , Guu H  F , Chen Y  F , Chuan S  T , Chen L  Y , Wang C  Y , Hong J  J , Wang T 
Published: July 2024

Abstract

Study question
Is there a correlation between different female infertility factors and displaced window of implantation?

Summary answer
Patients with decreased ovarian reserve and endometriosis have higher risk in experiencing displaced window of implantation.

What is known already
Numerous studies substantiate that infertility stems from various etiology, including ovulatory dysfunction, male factors, tubal disease, endometriosis, uterine factors...etc. MicroRNAs (miRNAs) play a crucial role in initiating these infertility-related disorders and influencing biological processes like gametogenesis, embryogenesis, ovarian, uterine or endometrial condition. Notably, miRNAs regulate endometrial receptivity, suggesting optimal embryo transfer timing during IVF treatment by identifying the window of implantation (WOI). In recognition of this significant function, MIRA, a molecular testing solution that predicts endometrial receptivity for patients undergoing frozen embryo transfer (FET) by targeting miRNA biomarkers, was developed in hopes of bolstering success rate for personalized embryo transfer.

Study design, size, duration
This study aims to identify if there is a correlation seen between female infertility factors and the WOI. We enrolled a total of 96 patients who demonstrated successful pregnancy outcomes following personalized embryo transfer. The patients’ personalized embryo transfer timing recommendations were assessed based on their miRNA expression profiles using MIRA. Concurrently, the participants’ underlining infertility diseases were classified according to diagnoses guidelines provided by Taiwan’s Ministry of Health and Welfare.

Participants/materials, setting, methods
Six categories of female infertility diseases were included: decreased ovarian reserve, tubal, endometriosis, uterine abnormalities (excluding myoma and adenomyosis), polycystic ovary syndrome (PCOS), and myoma factors. Infertile factors such as unexplained, aneuploid oocyte (PGT), male factors, and adenomyosis were excluded due to limited sample size.
Statistical analysis of endometrial stages and disease categories involved calculating percentage of the window of implantation (WOI) versus displaced WOI (either pre- or post-receptive) within the six types of diseases.

Main results and the role of chance
Our result showed that overall, 64.58% of 96 patients have a receptive window of implantation. Compared to this baseline, polycystic ovary syndrome (66.67%) does not elevate the risk of displaced endometrial stages. However, patients with decreased ovarian reserve and endometriosis are more likely to display displaced window of implantation, with average rates of 57.14% and 55.56% WOI respectively. Notably, patients with uterine abnormalities (84.62%) and myoma (87.5%) factors exhibit a lower likelihood of having a displaced WOI. The WOI percentage caused by tubal factors is slightly lower at 76.19%.
In conclusion, these preliminary findings establishes that categories of female infertility diseases have discernible effects on patients’ WOI. As patients with certain infertility factors, such as decreased ovarian reserve and endometriosis, demonstrated a greater risk in experiencing displaced WOI, patients that fall under these categories could further benefit from utilizing endometrial receptivity testing to determine the optimal timing for their embryo transfer to potentially improve their reproductive outcomes and facilitate shared decision-making (SDM) in patient’s embryo transfer process.

Limitations, reasons for caution
While this result offers a preliminary overview for the correlation between endometrial stages and female infertility diseases, we cannot confirm whether these conclusions reached statistical significance due to the limitation of data.

Wider implications of the findings
Further investigation into the specific reasons for the discernable WOI patterns in different diseases is warranted in larger sample sizes to offer more personalized and robust clinical information supporting IVF treatments.

Trial registration number
’not applicable’