Abstract
BACKGROUND: The positive effects of growth hormone (GH) on the endometrium, including increased endometrial blood supply and enhanced expression of cytokines associated with endometrial receptivity, have been noted. However, data on the effect of GH on the endometrium remain limited. OBJECTIVES: This study aimed to investigate the effect of intrauterine administration of GH on the IVF success rate in women with recurrent implantation failure (RIF). METHODS: This randomized double-blind clinical trial was conducted on 60 infertile women under 40 years old with a Body Mass Index (BMI) below 30 kg/m², all diagnosed with RIF-defined as at least three failed pregnancies after transferring a minimum of four good-quality embryos due to unknown causes. Women with uterine malformations, Asherman syndrome, cavity-distorting lesions, severe endometriosis, or other underlying diseases were excluded. After six days of estrogen therapy, transvaginal ultrasound (TVS) was performed to measure and compare the thickness and quality of the endometrium. Participants were divided into two groups. In the intervention group, 10 units of GH were administered using an IUI catheter positioned one centimeter above the cervical os. Study outcomes included changes in endometrial thickness (ET) and quality, as well as pregnancy rates. Primary endpoints were changes in ET and quality, while secondary endpoints were pregnancy rates. Adverse drug responses were also evaluated. RESULTS: The mean age was 34.96 ± 4.04 years, and the mean BMI was 24.89 ± 2.91 kg/m², with no significant differences in baseline variables between the study groups. The average ET on the 8th day of the cycle was 5.38 ± 0.96 mm in the intervention group and 5.20 ± 0.80 mm in the control group, showing no significant difference (P = 0.467). The ET on the day of initiating progesterone was 7.60 ± 1.03 mm in the intervention group and 7.40 ± 0.60 mm in the control group, with no significant difference (P = 0.264). The odds ratio for achieving a high-quality endometrium was 2.37 (95% CI 0.80 - 6.98, P = 0.116) for the GH group compared to the non-GH group. The odds ratio for achieving a clinical pregnancy was 3.06 (95% CI 0.54 - 17.37, P = 0.205) for the GH group compared to the non-GH group. Two cases of cervicitis were reported in the GH group. CONCLUSIONS: Intrauterine administration of GH appears to enhance endometrial receptivity in women with RIF.