Fertility and pregnancy under methotrexate | Side effects of Methotrexate

Fertility and pregnancy under methotrexate

Methotrexate has a teratogenic effect, i.e. it damages the embryo or the “maturing fruit”, if one wants to translate the term literally. Therefore, methotrexate therapy is not possible during pregnancy. It can lead to hereditary damage to the embryo, and in the worst case to abortion.

Even after discontinuing methotrexate therapy, damage to the eggs and sperm can still occur for up to six months. Therefore, appropriate contraception must be guaranteed for this period. However, fertility itself is not affected by methotrexate therapy in women.

In men, there may be a reduction in the number of sperm. However, this returns to normal after the end of the therapy. A reduced sperm count cannot be detected externally – i.e. by the amount of ejaculate – because the sperm themselves only account for a good 1% of the ejaculation. In addition, the amount of ejaculation varies from person to person anyway, and fluctuates between 2 and 6 milliliters.