RESEARCH QUESTION: While growth hormone (GH) is hypothesized to potentially enhance embryo quality, results of current basic and clinical researches remain inconclusive. This study assesses the effect of GH supplementation on embryo quality and explores the relationship between baseline insulin-like growth factor-1 (IGF-1) levels and the efficacy of GH supplementation among Chinese patients undergoing in vitro fertilization (IVF). DESIGN: A randomized controlled Open-label trial was performed with 128 women experiencing poor embryonic development in IVF. Participants were allocated to the GH group (GH + Gonadotropin-Releasing Hormone [GnRH] antagonist protocol) and the Control group (GnRH antagonist protocol). The primary outcome was the number of high-quality embryos on Day 3. RESULTS: Patients in the GH group required significantly lower total doses of gonadotropin (2213 ± 667 IU vs. 2573 ± 630 IU, p = 0.0058) and shorter duration of controlled ovarian stimulation (10.1 ± 1.60 days vs. 10.6 ± 1.30 days, p = 0.0488). While there was no statistically significant overall increase in the number of high-quality embryos, subgroup analysis indicated that patients with lower baseline IGF-1 levels, especially those below the lowest quartile, might show a higher rate of high-quality embryos with GH supplementation (p = 0.0488). Additionally, the fresh embryo transfer clinical pregnancy rate was numerically higher in the GH supplementation group (46.2%) compared to the control group (38.5%), although not statistically significant. CONCLUSIONS: This study suggests that GH co-treatment may enhance ovarian responsiveness in IVF patients with poor embryo quality, thereby reducing the dosage and duration of Gonadotropin (Gn) administration. Among individuals with lower IGF-1 levels, adding GH may improve the rate of high-quality embryos, highlighting the potential benefits of personalized treatment strategies in IVF. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov ID: NCT03966339 (Registration time: 2019-05-24).