Evidence check: COMT in the context of fertility

COMT (catechol-O-methyltransferase) is involved in estrogen metabolism. Variants like Val158Met can alter estrogen clearance and have been linked to fertility outcomes, endometriosis, and recurrent pregnancy loss. However, evidence is moderate and not sufficient for clinical recommendations. Most studies are associative with small effect sizes. Lifestyle, hormonal status, and other genetic factors are more influential. COMT testing alone is not established for fertility assessment. Be cautious of overinterpretation by direct-to-consumer tests. Evidence level: human-moderate / mixed.