How are SHBG and Fruchtbarkeit related?

SHBG (sex hormone-binding globulin) modulates the bioavailability of sex steroids. Low SHBG – often linked to insulin resistance, obesity, or PCOS – elevates free androgen levels and can impair ovulation and fertility in women. In men, very low SHBG is associated with reduced sperm quality. Conversely, high SHBG (e.g., in hyperthyroidism or liver disease) lowers free testosterone and may also reduce fertility. Evidence is based on observational studies and mechanistic plausibility; no large RCTs have tested SHBG-targeted interventions for fertility. Measuring SHBG as part of a fertility workup can provide clues, but it should be interpreted alongside other hormones and metabolic markers. Caveat: SHBG levels vary widely and are not a standalone fertility predictor.