Empirical use of growth hormone in IVF is useless: the largest randomized controlled trial

STUDY QUESTION Does adjuvant growth hormone (GH) therapy in GnRH antagonist cycles improve reproductive outcomes in the general IVF population? SUMMARY ANSWER Empiric adjuvant GH therapy in GnRH antagonist cycles does not improve IVF stimulation results or reproductive outcomes, including implantation, miscarriage, and clinical pregnancy rates. WHAT IS KNOWN ALREADY Previous evidence regarding the benefits of GH therapy in IVF cycles has been inconclusive due to the lack of well-designed, large-scale randomized controlled trials (RCTs) in the general IVF population. STUDY DESIGN, SIZE, DURATION This is a phase III open-label RCT involving 288 patients undergoing antagonist IVF cycles at the Ovo clinic in Montreal, Canada, between June 2014 and January 2020. Patients were randomly assigned at a 1:1 ratio to either the GH or control group. The intervention group received daily 2.5 mg subcutaneous injections of GH from Day 1 of ovarian stimulation until the day of oocyte retrieval, while the control group received standard ovarian stimulation without any adjuvant therapy. PARTICIPANTS/MATERIALS, SETTING, METHODS Patients were expected normal responders. All embryo transfers, both fresh and frozen, resulting from the studied IVF cycle were included in an intention-to-treat and per-protocol analyses. The primary outcome was the clinical pregnancy rate, while secondary outcomes included the number of retrieved oocytes, good-quality embryos, maturation, fertilization, implantation, and miscarriage rates. MAIN RESULTS AND THE ROLE OF CHANCE A total of 288 patients were recruited and randomly assigned at a 1:1 ratio to either the GH or the control group. After excluding cycle cancellations and patients who did not undergo transfer, 105 patients remained in each group. The overall mean age was 38.0 years, the mean BMI was 25.11 kg/m2 and the mean anti-Müllerian hormone was 2.51 ng/ml. The cycle characteristics were similar between both groups. No differences were observed regarding the total dose of gonadotropins (4600 versus 4660 IU for the GH and control groups, respectively, P = 0.752), days of stimulation (11.4 versus 11.7 days, P = 0.118), and endometrial thickness (10.63 versus 10.94 mm, P = 0.372). Both the intention to treat (ITT) and per protocol analyses yielded similar results for stimulation outcomes. In the ITT analysis, no differences were found in the number of follicles ≥15 mm (7.8 versus 7.1, P = 0.212), retrieved oocytes (11.7 versus 11.2, P = 0.613), mature oocytes (8.5 versus 8.6, P = 0.851), maturation rate (73.8 versus 78.4%, P = 0.060), fertilization rate (64.3 versus 67.2%, P = 0.388), and good quality embryos (2.5 versus 2.6, P = 0.767). Reproductive outcomes in fresh embryo transfer showed no difference for implantation rate (38.2 versus 39.5%, P = 0.829), miscarriage rate (26.5 versus 31.1%, P = 0.653), clinical pregnancy rate (43.6 versus 50.0%, P = 0.406, rate difference, 95% CI: −0.06 [−0.22, 0.09]), and live birth rate (32.1 versus 33.3%, P = 0.860). The number of embryos needed to achieve a clinical pregnancy was 3.0 versus 2.5 in the GH and control groups, respectively. Similarly, reproductive outcomes in first frozen embryo transfer showed no difference for implantation rate (31.6 versus 45.3%, P = 0.178), miscarriage rate (28.6 versus 26.3%, P = 0.873), clinical pregnancy rate (35.1 versus 44.2%, P = 0.406, P = 0.356, rate difference, 95% CI: −0.09 [−0.28, 0.10]), and live birth rate (22.8 versus 32.6%, P = 0.277). The number of embryos needed to achieve a clinical pregnancy was 3.1 versus 2.4 in the GH and control groups, respectively. LIMITATIONS, REASONS FOR CAUTION The study focused on expected normal responders, limiting its applicability to other patient populations such as poor responders. WIDER IMPLICATIONS OF THE FINDINGS These findings suggest that adding GH therapy to ovarian stimulation in GnRH antagonist cycles may not benefit the general IVF population. Additional high-quality RCTs are warranted to identify subgroups of patients who might benefit from this treatment. STUDY FUNDING/COMPETING INTEREST(S) EMD Serono Inc., Mississauga, Canada, supplied Saizen® for the study, free of charge. In addition, they provided funding for the statistical analysis. I-J.K. declares grants or contracts from Ferring Pharmaceuticals, consulting fees from Ferring Pharmaceuticals, honoraria from Ferring Pharmaceuticals and EMD Serono, support for attending meetings or travel from Ferring Pharmaceuticals and EMD Serono, participation on a Data Safety Monitoring Board or Advisory Board for Ferring Pharmaceuticals, and stock or stock options from The Fertility Partners; W.J. declares support for attending meetings or travel from EMD Serono; and S.P. declares stock or stock options from The Fertility Partners. All other authors have no conflicts of interest to disclose. TRIAL REGISTRATION NUMBER NCT01715324. TRIAL REGISTRATION DATE 25 October 2012. DATE OF FIRST PATIENT’S ENROLMENT 25 June 2014.