Importance of controlled liquefaction periods for valid steroid assays in human seminal plasma.

Incubation of seminal plasma for different periods up to 24 hours at room temperature resulted in a marked gradual increase in the levels of unconjugated pregnenolone, dehydroepiandrosterone, and testosterone, whereas no alterations were detected in unconjugated dihydrotestosterone and estradiol. No significant difference was observed in the levels of the most sensitive indicators of artifactual changes, pregnenolone and dehydroepiandrosterone, when seminal plasma was frozen immediately or within 30 minutes of ejaculation. It is suggested that, at least when steroid analyses in seminal plasma are contemplated, the samples of ejaculate should be provided by masturbation on hospital premises so that the necessary liquefaction period can be kept short, approximately 30 minutes.