What role does CYP1A2 play in fertility?

CYP1A2 is an enzyme involved in metabolizing caffeine and estrogens. Genetic variants (e.g., rs762551) can classify individuals as 'fast' or 'slow' metabolizers. Regarding fertility, the proposed mechanism is that altered estrogen clearance may affect hormone balance and ovulation. Additionally, high caffeine intake, which is processed by CYP1A2, has been associated with delayed conception in some observational studies. However, the evidence is primarily mechanistic and observational; there are no robust clinical trials linking CYP1A2 genotype directly to fertility outcomes. Effect sizes are small, and confounding factors (diet, lifestyle, age) are major. Consumer DNA tests may report CYP1A2 status, but this information is not clinically actionable for fertility. Caveat: do not make fertility decisions based solely on a CYP1A2 test; consult a reproductive specialist for comprehensive evaluation.