Spermatogenesis in Men Treated with Subcutaneous Application of Levonorgestrel and Estrone Rods

¹ Urological Department, General Hospital, Salzburg, Austria
² Steroid Research Laboratory, Department of Medical Chemistry, University of Helsinki, Helsinki, Finland

The effects of a combination of a progestin, levonorgestrel (LNg), and estrone (E₁), on exocrine and endocrine testicular function were examined in adult men. The mode of administration was subcutaneously implanted dimethyl polysiloxane rods impregnated with either of the two hormones. The technical data on the rods used are as follows: length 30 mm, outer diameter 2.4 mm, hormone content/rod approximately 40 mg of LNg or E₁. The subjects enrolled in the study were divided into two regimen groups: group A received six levonorgestrel and three estrone rods; group B, ten levonorgestrel and six estrone rods. The rods were implanted subcutaneously in the submammillary region. Complete spermatogenic arrest of variable duration was achieved in eleven of 13 subjects. In the two nonresponders, spermatogenesis was completely unaffected by the treatment. All subjects complained of some decrease of libido, erections, and potency, particularly during the first three to four months after initiation of treatment when testosterone in serum was at Its lowest levels. Clinical evaluations and measurements of various urine and serum components revealed no significant changes during the treatment period. The combination of LNg and E₁ administered in this fashion was not adequate to achieve spermatogenic arrest in all subjects, including the period when the hormone-bearing rods were still in place. Consequently, this regimen is not judged to hold promise as a method of fertility regulation.

     Key words: spermatogenic arrest, silastic rods, hormone-impregnated, subcutaneous implantation, levonorgestrel, estrone

Submitted on October 2, 1980
Revised on March 24, 1981
Accepted on May 27, 1981