Intrauterine infusion of human chorionic gonadotropin before embryo transfer in IVF/ET cycle: The critical review

Abstract

Intrauterine infusion of human chorionic gonadotropin (IUI‐hCG) has been proposed to improve the outcome of in vitro fertilization‐embryo transfer (IVF‐ET), since it plays a critical role in synchronizing endometrial and fetal development. As the early mediator from embryo, hCG promotes the decidualization, angiogenesis, maternal immune tolerance, and trophoblast invasion, favoring successful implantation of embryo. Although multiple clinical trials have been conducted to verify the efficacy of IUI‐hCG on IVF‐ET outcome in recent years, the findings remained controversial. The difference in study design and population might be the cause to the different consequences after administration of hCG. More importantly, the endometrial receptivity, which might affect the efficacy of IUI‐hCG, has not been assessed in women receiving this intervention. Selecting the right population suitable for IUI‐hCG based on known etiology would be crucial in enhancing its efficacy and minimize any possible complications. Investigation of optimal indications for IUI‐hCG should be highlighted in the future.

Granulocyte colony stimulating factor versus human chorionic gonadotropin for recurrent implantation failure in intra cytoplasmic sperm injection: a randomized clinical trial

“…However, the effect of HCG on immune response during implantation is still unclear. Previous studies found that it boosted proangiogenic factors within the endometrium, modified uNK production, elevated Tregs, and increased trophoblastic invasion [ 24 – 26 ]. Mansour et al were the first to investigate the use of IU HCG in women who underwent IVF in 2011 and found that it increased both pregnancy and implantation success rates [ 27 ].…”

Intrauterine perfusion immunotherapies in recurrent implantation failures: Systematic review

“…The impact of using hCG on immunological mechanisms during embryonic implantation is unknown. Studies have shown that hCG increases endometrial levels of proangiogenic factors (VEGF and insulin‐like growth factor II), modulates the proliferation of uNKs, and raises levels of Tregs and CD4 + /CD25 + /Foxp3 + , and trophoblastic invasion 51‐53 …”

Human chorionic gonadotropin‐mediated modulation of pregnancy‐compatible peripheral blood natural killer cells in frozen embryo transfer cycles

“…One subcutaneous injection of hCG at the initiation of progesterone for transition to the secretory phase may improve endometrial/blastocyst synchrony, while also stabilizing the resident immune cells essential for effective implantation and placentation. Alternative routes of hCG administration have been reported, including intrauterine infusion of hCG (IUI‐hCG) 64,65 . While initial reports show promise, additional well‐controlled studies are required prior to recommending mainstream use of hCG as an immune modulator in reproductive medicine.…”