Personalizing gonadotropin treatment in male infertility: how APHRODITE may help

Group 1 (hypogonadotropic hypogonadism, low FSH and low T): gonadotropins are mandatory; HCG alone or HCG+FSH restores spermatogenesis in most patients. Sperm retrieval in untreated hypo-hypo azoospermic men almost always fails. Group 2 (idiopathic oligozoospermia, normal hormones, abnormal semen): FSH monotherapy supported by meta-analysis with pregnancy OR 1.6, conditional recommendation in most guidelines. Group 3 (idiopathic + low T): FSH+HCG combination restores endocrine balance. Group 4 (elevated FSH, NOA): 80% have biochemical hypogonadism; pre-micro-TESE gonadotropin therapy is the strongest predictor of sperm retrieval success in a 600+ patient series, with stronger signal in group 3 than 4. Group 5 (normal semen, unexplained): research frontier — is normal truly optimal?

What this means in practice

Stop treating all idiopathic male infertility as one category. Map every infertile man into one of the five APHRODITE groups before deciding on gonadotropin therapy. Use FSH monotherapy in group 2; FSH+HCG in groups 1 and 3; pre-micro-TESE hormonal optimisation in group 4 — especially when FSH sits within the upper-normal range. Treat the framework as a decision-making tool, not a label.

Caveats

APHRODITE is a stratification system, not a treatment prescription. Most meta-analytic data on FSH therapy in idiopathic infertility precede the framework, so regimens were not phenotype-optimised. Group 5 (normal semen, unexplained) remains a research question — extrapolating from primate data is not yet a clinical recommendation. Heterogeneity within each group remains; receptor polymorphisms and downstream Sertoli-cell function are not captured by FSH/LH/T alone.