Multiple sclerosis and pregnancy in the 'treatment era'.

The influence of pregnancy on the course of multiple sclerosis (MS) has long been controversial; until the end of 1990s, women with MS were discouraged from having children owing to a biased belief that pregnancy would worsen the disease course. Since the first large prospective study in 1998, counselling of women with MS has changed radically, and many patients have attained their desire of motherhood. Although many disease-modifying drugs have come to market in the past two decades, when used during pregnancy and lactation, their beneficial effects on the course of MS have to be balanced with fears concerning potential risks to the fetus or child. The wealth of treatment options and the various associated risks have created a growing need for counselling on family planning for women with MS. Most importantly, such counselling should address the concerns that women with MS might have regarding pregnancy. Second, as soon as a woman starts considering pregnancy, a treatment plan should be established. This plan needs to weigh the risk posed to the fetus by potentially harmful drug exposure, and the risk to the mother from a reappearance of disease activity. Finally, breastfeeding and treatment options after delivery should be discussed to outline the options for prevention of postpartum relapses, and the possible resumption of disease-modifying drugs.