Effects of Intrauterine Infusion of G-CSF and HCG on Peripheral Blood Treg and Pregnancy Outcome in Patients with Thin Endometrium Undergoing Frozen-thawed Embryo Transfer.

Background: Patients with thin endometrium undergoing frozen-thawed embryo transfer often encounter challenges with pregnancy outcomes. Enhancing endometrial receptivity and immune tolerance may improve these outcomes.

Objective: To investigate the effects of intrauterine perfusion of granulocyte colony-stimulating factor (G-CSF) and human chorionic gonadotropin (HCG) on regulatory T cells (Tregs) and pregnancy outcomes in patients with thin endometrium undergoing frozen-thawed embryo transfer.

Methods: 150 patients with thin endometrium were randomly assigned to three groups: a control group that received no intervention, an HCG group, and a G-CSF group. The effectiveness of the treatments was assessed by comparing uterine parameters, Treg levels, and pregnancy outcomes across the groups.

Results: The HCG and G-CSF groups exhibited significant improvements compared to the control group, including increased endometrial thickness, enhanced blood flow, higher expression of endometrial receptivity markers (integrin αvβ3, osteopontin), and elevated Treg levels. Notably, the G-CSF group demonstrated even greater enhancements compared to the HCG group, with significantly higher endometrial thickness, better blood flow, increased receptivity markers, and elevated Treg levels. Additionally, the G-CSF group achieved significantly higher biochemical and clinical pregnancy rates compared to both the HCG and control groups. This highlights the potential of G-CSF in improving pregnancy outcomes for patients with a thin endometrium.

Conclusion: The intrauterine perfusion of G-CSF significantly enhanced pregnancy outcomes in patients with thin endometrium by improving endometrial blood flow, immune tolerance, thickness, Treg induction, and embryo implantation. These findings suggest that G-CSF could be a promising therapeutic option for this patient population.