In vitro fertilization outcome following embryo transfer with or without preinstillation of human chorionic gonadotropin into the uterine cavity: A randomized controlled trial

Background: Intrauterine injection of human chorionic gonadotropin (hCG) at embryo transfer (ET) has been shown to improve the outcome of assisted reproductive techniques. The aim of this study was to confirm previous findings. Methods: In this randomized controlled trial, 483 infertile women who were candidates for in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) for the first time were randomly assigned to receive an intrauterine injection of 500 IU hCG or placebo (tissue culture media) before ET. The main outcome measures were implantation and clinical pregnancy rates. Results: Both the hCG-treated group (n = 240) and control group (n = 243) were similar at baseline in terms of demographic and obstetrical characteristics. There were significant differences between the two groups regarding the implantation rate (23.6 vs. 12.2%, p < 0.001), pregnancy rate (54.6 vs. 35.8%, p < 0.001), clinical pregnancy rate (50 vs. 32.1%, p < 0.001), ongoing pregnancy rate (15.3 vs. 9.2%, p < 0.001) and live delivery rate (14.3 vs. 8.4%, p < 0.001). The rate of fertilization and abortion rates were not statistically different. Conclusion: Intrauterine injection of hCG before ET improves implantation and pregnancy rates and may be considered an adjuvant in IVF/ICSI.