Klinefelter syndrome: an argument for early aggressive hormonal and fertility management

ObjectiveTo investigate the impact of early hormone replacement therapy (HT) on sperm retrieval rates in patients with Klinefelter syndrome (KS).DesignA systematic review of the relevant literature using the PubMed NLM database.Result(s)There are no randomized controlled trials evaluating the impact of HT on sperm retrieval or reproductive outcomes in men with KS. On average, surgical sperm retrieval rates in men with KS are around 51%, with a range of 28%–69%. Young patient age is the most consistent positive predictor of sperm retrieval. Lower retrieval rates have been reported in a small subset of KS adults who previously received exogenous T, although the nature, duration, and reason for such therapy in these patient subsets are unknown.Conclusion(s)Early HT is recommended in patients with KS, but its effect on fertility potential has not been definitively studied. Larger studies are needed to better answer this question. Cryopreservation of sperm-containing semen or testicular tissue from a significant proportion of affected adolescents is possible, even when containing very low numbers of spermatozoa, and should be considered to maximize future fertility potential.