P-489 Uterine fluid-immune cell analysis at the time of the embryo transfer

Abstract Study question What are the subtypes of immune cells present in upper and lower parts uterus at time frozen embryo transfer (FET)? Summary answer Our study is first confirming different cell subsets freshly collected uterine fluid transfer. known already Although endometrial receptivity a key factor influencing implantation both naturally conceived assisted reproductive technology (ART) cycles, very little about endometrium milieu around implantation. Previous studies have demonstrated presence several cytokines affect However, there lacking data within cavity design, size, duration This was approved by Institutional Review Board (# 49174). The designed as prospective observational cohort between May 2021 December 2022 single academic-based fertility center. All patients underwent least one In Vitro Fertilization cycle (IVF) embryos. Twenty-four participants were recruited for this which conducted during (FET) regardless outcome previous cycles. Participants/materials, setting, methods Trial catheter introduced under ultrasound guidance into segment. Upon removal, tip rinsed IMDN medium containing 10% FBS (lower). Embryo then placed guidance. separate aliquot above media (upper). After centrifugation, pelleted stained following surface markers: CD45, CD3, CD19, CD4, CD8, gamma delta TCR, CD25, CD127, CD66b, CD14, CD16, CD56. Main results role chance staining cells, we able to identify viable leukocytes from samples obtained both, (0.1257 x 106 +/- SD 0.3167), (0.1230 0.1171), respectively. Among total no significant difference percent number CD45+ (9.880 6.983, 13.67 9.792, p = 0.1980) significantly higher expression CD3 + (p 0.006), CD19 0.0319) CD14 0.0189) compared uterus. Within all CD3+ found that T (GDT) major population contrast, CD8+ when 0.009). There statistically CD4+ regulatory NK (CD56+), neutrophils (CD66b+) monocytes (CD14+) Limitations, reasons caution Limitations our include well parameters analyzed flow cytometry. To maximize information each sample, multicolor cytometry can give critical insight composition Wider implications findings We believe will Understanding guide further research identifying optimal milieus favor Comprehensive analysis expected lead new diagnostic therapeutic approaches improve IVF outcomes. registration not applicable