Evidence check: CYP1A2 in the context of fertility

CYP1A2 metabolizes caffeine and estrogens. Some studies suggest that genetic variants (e.g., rs762551) alter enzyme activity and may indirectly affect fertility parameters like cycle length or IVF outcomes. However, the evidence is weak: mostly mechanistic or small observational studies, not large GWAS or clinical guidelines. The effect is modest and confounded by lifestyle factors (caffeine intake, smoking, hormonal status). Consumer DNA tests often overclaim clinical relevance. A CYP1A2 test alone is not suitable to diagnose or treat fertility issues. For infertility, comprehensive medical workup (hormone panel, semen analysis, cycle monitoring) is essential. Safety note: High caffeine intake in slow metabolizers (CYP1A2*1F) may increase miscarriage risk – but this is not a direct fertility test.