Examination of the effects of methotrexate on histological and steroid receptor changes in the endosalpinx of the rat

These results provide the first evidence that MTX (≥5 mg/kg) can induce long-term, irreversible damage to steroid hormone receptors in the fallopian tubes in a dose-dependent manner. We tentatively suggest that MTX should be used in a relatively small and safe range of dosage in order to avoid impairment and potential risk of subsequent tubal pregnancy or infertility.