Final Results from the AVONEX(R) (Intramuscular Interferon Beta-1a) Pregnancy Exposure Registry (P06.191)

Pregnancy and the Use of Disease-Modifying Therapies in Patients with Multiple Sclerosis: Benefits versus Risks

The burden of multiple sclerosis (MS) in women of childbearing potential is increasing, with peak incidence around the age of 30 years, increasing incidence and prevalence, and growing female : male ratio. Guidelines recommend early use of disease-modifying therapies (DMTs), which are contraindicated or recommended with considerable caution, during pregnancy/breastfeeding. Many physicians are reluctant to prescribe them for a woman who is/is planning to be pregnant. Interferons are not absolutely contraindicated during pregnancy, since interferon-β appears to lack serious adverse effects in pregnancy, despite a warning in its labelling concerning risk of spontaneous abortion. Glatiramer acetate, natalizumab, and alemtuzumab also may not induce adverse pregnancy outcomes, although natalizumab may induce haematologic abnormalities in newborns. An accelerated elimination procedure is needed for teriflunomide if pregnancy occurs on treatment or if pregnancy is planned. Current evidence supports the contraindication for fingolimod during pregnancy; data on other DMTs remains limited. Increased relapse rates following withdrawal of some DMTs in pregnancy are concerning and require further research. The postpartum period brings increased risk of disease reactivation that needs to be carefully addressed through effective communication between treating physicians and mothers intending to breastfeed. We address the potential for use of the first- and second-line DMTs in pregnancy and lactation.

Multiple sclerosis and pregnancy: therapeutic considerations

For women with multiple sclerosis (MS) who become pregnant, the risks and benefits of ongoing therapy for the health of both the mother and the fetus must be carefully considered. Based on a literature review and our MS center's standard practices, we provide guidance to aid clinical decision making in the absence of clear evidence-based clinical practice guidelines. Women seeking to achieve pregnancy should generally discontinue disease-modifying therapy use prior to attempting conception. For example, the immunosuppressant mitoxantrone is teratogenic and should be prescribed only with the assurance of effective contraception. Conception should be discouraged for patients on fingolimod, because of the limited information available on human pregnancy outcomes. Current evidence, including data from pregnancy registries for glatiramer acetate (GA), interferon beta-1a (IFNβ-1a), and natalizumab, has not shown specific patterns of malformations suggesting teratogenicity. Pregnancy registry data have not been published for IFNβ-1b. During breastfeeding, intravenous immunoglobulin and corticosteroids are generally safe and may be associated with a reduction in postpartum relapses; however, a washout period is recommended between corticosteroid administration and the resumption of breastfeeding. Clinical data on the use of IFNβ, GA, and natalizumab during lactation are limited. Mitoxantrone is contraindicated during breastfeeding, and fingolimod should be avoided in nursing mothers, because of a lack of data.