Multiple sclerosis does not affect the fertility of men or women, nor does it affect a woman’s ability to become pregnant. Women of childbearing age should only become pregnant during the period of stable disease and resume treatment immediately after delivery; during pregnancy, treatment should be temporarily stopped or postponed, called a “treatment holiday”; if the patient is in a critical period of treatment, treatment should continue and pregnancy should be postponed until after treatment is completed. Women should only become pregnant while their MS disease is stable. If a woman is being treated for multiple sclerosis, she should consult with a neurologist or obstetrician/gynecologist once she decides to conceive. During pregnancy, treatment will have to be temporarily stopped or postponed, which is often referred to as a “treatment holiday”. During this time it is necessary to conceive as soon as possible and to resume treatment as soon as the child is born. If an atopic treatment is in a critical period, the treatment should be continued and the pregnancy postponed until the end of the treatment, when an appropriate time is chosen to conceive.