Growth Hormone Therapy in Recurrent Implantation Failure: Stratification by FSH Receptor Polymorphism (Asn680Ser) Reveals Genotype-Specific Benefits.

Recurrent implantation failure (RIF) remains a challenging clinical problem. Growth hormone (GH) co-treatment has been explored as an adjunct in poor responders and RIF patients, with inconsistent evidence of benefit. This prospective cohort study assessed the impact of GH supplementation in 91 RIF patients undergoing in vitro fertilization, stratified by FSHR (follicular stimulating hormone receptor) genotype Asn680Ser with or without GH supplementation. Patients were stratified by FSHR genotype into homozygous Ser/Ser versus Ser/Asn or Asn/Asn groups. Overall, GH co-treatment conferred modest benefits in the unselected RIF cohort, limited to a higher cumulative live birth rate compared to controls and elevated leukemia inhibitory factor (LIF) levels (p < 0.05 both). When stratified by FSHR genotype, the Ser/Ser subgroup exhibited markedly better outcomes with GH. These patients showed a higher (0.5 vs. 0.33, p = 0.003), produced more embryos (2.88 vs. 1.53, p = 0.02), and had a markedly improved cumulative live birth rate-50% with GH versus 13% without-highlighting a clinically meaningful benefit of GH in the Ser/Ser subgroup. No significant benefit was observed in Asn allele carriers. These findings suggest that FSHR genotyping may help optimize treatment selection in RIF patients by identifying those most likely to benefit from GH supplementation.