Effects of growth hormone on pregnancy rates of patients with thin endometrium

N. Cui, A.-M. Li, Z.-Y. Luo, Z.-M. Zhao, Y.-M. Xu, J. Zhang, A.-M. Yang, L.-L. Wang, G.-M. Hao, B.-L. Gao

To investigate whether growth hormone (GH) could improve pregnancy rates of patients with thin endometrium by clinical study and laboratory experiments. Ninety-three patients were randomized to either the GH-received group (40) or the routine exogenous administration of estrogens control group (53) for clinical study. The human endometrial carcinoma cell line RL95-2 was used for testing the role of GH with Western blot and real-time PCR by exposure to various concentrations of GH (0.1 nM,1 nM,10 nM,100 nM). Patients treated with GH had a significantly (P < 0.05) greater endometrium thickness on day 3 (7.87±0.72 vs 6.34±0.86), higher implantation rates (24.4% vs 10.5%) and greater clinical pregnancy rates (42.5% vs 18.9%) compared with the control group. No adverse events were associated with the use of GH. Administration of GH significantly up-regulated the expression of VEGF, ItgB3 and IGF-I expression in RL95-2 cells at both mRNA and protein levels (P < 0.05). AG490, an inhibitor of JAK2, nearly completely inhibited the up-regulative effect of GH through the JAK2-STAT5 pathway, and GH-induced effects could be mediated through autocrine IGF-I together with its hepatic counterpart. IGF-I mRNA was detected in the RL95-2 cells. GH may improve pregnancy outcomes of patients with thin endometrium who undergo frozen embryo transfer by acting on human endometrial cells to promote proliferation and vascularization and to up-regulate receptivity-related molecular expression.