The use of MS medication is contraindicated during pregnancy. The reason for this is that the possible consequences of the medication for the unborn child are not sufficiently known. Research on pregnant laboratory animals has shown that some products have a harmful effect. Treatment is usually stopped for a woman, in consultation with the neurologist, as soon as a couple stop using contraception.

The functioning of the immune system naturally slows down a bit during pregnancy. The risk of a relapse, especially in the third trimester, is therefore lower than normal.  This risk then increases again in the first three to six months after the birth. Breastfeeding can however have a protective effect. Out of safety considerations for the child, it's also best to avoid MS medication during the breastfeeding period.

MS does not have any effect on fertility in principle. Complaints with regard to sexuality (decreased libido, erectile dysfunction, etc.) can occur, however. It is recommended to consult a doctor if it takes longer to become pregnant than expected (generally one year). Hormonal stimulation in the framework of an in vitro fertilisation treatment can increase the risk of a relapse.