Before every dose of methotrexate is administered, it is mandatory to exclude pregnancy since the drug is known to cause foetal death and/or congenital anomalies (birth defects). It should not be used in pregnant women, or in those who might become pregnant. Women of childbearing potential should not be started on methotrexate until pregnancy is excluded and should be fully counselled on the serious risk to the fetus should they become pregnant while undergoing treatment. Pregnancy is to be avoided if either partner is receiving methotrexate, during and for a minimum of three months after therapy has ceased.