The presence of a CYP1A1 MspI (rs4646903) polymorphism associated with OCs exposure may affect spermatogenesis by modifying the metabolism of androgens. It was concluded that increased DDE-DDT (Dichlorodiphenyldichloroethylene-DDT) exposure affects semen motility, concentration and morphology, especially under the existence of CYP1A1 MspI (rs4646903) polymorphism.