Role of FSH to optimize adolescent testicular growth

Role of FSH to optimize adolescent testicular growth Zacharin et al. (1) have addressed an important issue in the management of hypogonadotropic hypogonadism (HH), ‘‘What hormonal agents to initially use to optimize sperm production for these young men?’’ Many clinicians have such a limited clinical volume of these patients that they have to go to the textbooks to select appropriate therapy. Standard management is to use T replacement to induce pubertal secondary sexual characteristics for HH males, but androgens do not enhance testicular growth and function. Early treatment with hCG makes sense to enhance testicular growth during the critical period of potential testicular growth of adolescence, but it has not been the standard of care. The role of FSH cotreatment has been controversial in the human male. Although FSH is critical to initiation of spermatogenesis in the rodent, its role in human testicular function is less clear. Because of the relatively high cost of FSH and the common induction of spermatogenesis with hCG alone, FSH has not commonly been included as part of the early treatment of men with HH. The investigators provide a retrospective comparison of patients treated with either hCG or hCG and recombinant FSH. The study is severely limited by its retrospective nature, the fact that the two treatment groups had different racial and ethnic backgrounds (Indian/Australian) and that the age of patients treated (up to age 31 years) is likely far older than optimal for testicular development. However, there is no obvious selection bias in the patients treated at each site, despite the fact that they were a continent apart, and the apparent difference in response with hCG and recombinant FSH strongly suggests that recombinant FSH provides some benefit in testicular growth and possibly ultimate testicular function for the patients receiving combined treatment.

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Therefore, what do I take away from this study for management of the adolescent with HH? First, it makes sense to use hCG in the pubertal period to acquire whatever potential for testicular growth could be acquired in this critical window of development rather than T alone. I typically titrate the hCG response to obtain a serum total T of at least 400–500 ng/dL. Second, although optimal testicular function might be obtained with hCG at puberty and FSH later, the limited, imperfect data presented suggest that at least a 6- to 9-month period of recombinant FSH or hMG treatment is reasonable to optimize ultimate testicular function. Of course, a definitive randomized trial would have been preferable, but the data presented are clinically useful for this clinical scenario. Peter N. Schlegel, M.D. Weill Cornell Medical College, New York, New York http://dx.doi.org/10.1016/j.fertnstert.2012.07.1137 You can discuss this article with its authors and with other ASRM members at http://fertstertforum.com/schlegelp-fsh-adolescenttesticular-growth/ Use your smartphone to scan this QR code and connect to the discussion forum for this article now.* * Download a free QR code scanner by searching for “QR scanner” in your smartphone’s app store or app marketplace.

REFERENCE 1.

Zacharin M, Sabin MA, Nair VV, Dagabdhao P. Addition of recombinant follicle-stimulating hormone to human chorionic gonadotropin treatment in adolescents and young adults with hypogonadotrophic hypogonadism promotes normal testicular growth and may promote early spermatogenesis. Fertil Steril 2012;98:836–42.

VOL. 98 NO. 4 / OCTOBER 2012