Abstract: Objective：To investigate the effect of recombinant human growth hormone (rhGH) on the clinical outcomes of those patients with normal ovarian response undergoing in vitro fertilization and embryo transfer (IVF-ET). Methods: A total of 180 patients with normal ovarian response undergoing IVF-ET in our hospital, from January 2014 to December 2016, were divided into two groups． The study group (n=91) received the routine long-term protocol of controlled ovarian hyperstimulation (COH) and rhGH treatment. The control group (n=89) only received the routine long-term protocol of COH. The basic characteristics and pregnancy outcomes of two groups were compared. Results：There were no significant differences in the duration of infertility, gonadotropin dosage, the ratio of type A endometrium and the number of transplanted embryos between the two groups (all P＞0.05). The age, BMI, endometrial thickness and the level of estrogen on hCG day and the number of embryo with high quality in the study group were significantly higher than those in the control group (P＜0.05). Compared with the control group, the study group had a limited increase in the implanting rate and clinical pregnancy rate（but P＞0.05）. Conclusions: In those patients with normal ovarian response undergoing IVF-ET, rhGH can promote the egg maturation, embryo and endometrial development, and improve the endometrial tolerance. However, rhGH can not improve the clinical pregnancy outcome of the patients with normal ovarian response.

Key words: Growth hormone, Fertilization, in vitro, Embryo transfer, Endometrium, Pregnancy outcome