Evidence check: Testosteron in the context of Fruchtbarkeit

The provided knowledge contexts contain no specific information on testosterone and fertility. In general, testosterone is important for male fertility: it supports spermatogenesis and libido. However, low testosterone does not equal infertility; many men with low levels father children. Conversely, exogenous testosterone (e.g., anabolic steroids) can suppress endogenous production and impair sperm quality. In women, testosterone plays a role in ovarian function but is rarely used as a fertility marker. Direct-to-consumer (DTC) tests for testosterone are often marketing-driven and do not provide clinically actionable diagnoses. The evidence for routine testosterone testing in fertility assessment is mixed: associations exist, but effect sizes are small and predictive value limited. Without specific symptoms (e.g., loss of libido, testicular atrophy), testing is not indicated. For fertility concerns, a specialist (andrologist, gynecologist) should be consulted for comprehensive evaluation. The sources here do not directly support this statement; the evidence is based on general medical knowledge.