Based primarily on animal experiments, several of the MS medications are not recommended for women who are pregnant or planning pregnancy, however, pregnancies do sometimes occur whilst taking medication. It is therefore very important to gather data on the outcomes for mother and child in these circumstances so that accurate advice and information can be provided to women in the future.

Several studies on pregnancy outcomes in women with MS taking disease-modifying therapies have been published recently which we have summarised below:

One study, published in the journal BMJ Open, from researchers in the USA, assessed women in the Betaseron Pregnancy Registry, measuring outcomes of interferonβ-1b (IFNβ-1b ) use in pregnant women. The Registry reports on 96 pregnant women with MS enrolled over a 3 year period. These women were followed up from their initial enrolment on the Registry, to the four-month paediatric visit. In 95 of these women, the IFNβ-1b exposure occurred within the first trimester. One woman had IFNβ exposure only in the third trimester.

The researchers report that the 96 pregnancies resulted in 86 live births. There were reports of 11 miscarriages, 2 stillbirths, and 5 births with structural abnormalities. The rates of these negative outcomes were not found to be significantly different to normal population comparison rates. No developmental concerns were identified at the four-month paediatric visit. Though this study is relatively small, making it difficult to draw firm conclusions, their findings suggest there was no significant pattern of negative outcomes associated with administration of IFNβ-1b during pregnancy.

Published recently in the journal JAMA Neurology, was a case series of 12 pregnant women with highly active MS who were treated with natalizumab (Tysabri). The women were exposed to medication during their third trimester of pregnancy, following an MS relapse requiring treatment. This report identified 10 infants with mild to moderate blood abnormalities, including low levels of platelets and red blood cells. Further analysis of umbilical cord blood in five infants found that all five were exposed to natalizumab in utero. The authors of this study recommend that during pregnancy and at delivery, careful consultation with a paediatrician be available to manage any complications relating to blood abnormalities in newborns exposed to natalizumab.

One further study from researchers in Switzerland reported on 66 pregnancies in women taking fingolimod (Gilenya) at the time of conception. Of these pregnancies, there were 28 live births, 9 spontaneous abortions, 24 elective abortions, and 5 pregnancies were ongoing at the time of the paper being published. Two infants had severe malformations, and there were 5 cases of abnormal development.

While this study is also too small to draw firm conclusions, fingolimod has also been shown to cause birth complications or abnormalities in animals. The researchers recommend that women should use contraception during fingolimod therapy and for two months afterwards.

Finally, an Italian study published in BMC Neurology reports on the rate of negative outcomes in pregnancies fathered by men with MS undergoing disease-modifying therapies. They report on 45 males taking disease-modifying medications (39 IFN-β, 6 glatiramer acetate), compared to 33 pregnancies that were not exposed to MS medications. The researchers found no differences between these groups in rates of spontaneous abortion or malformations, or in a range of birth outcomes including mean gestational age, frequency of caesarean, birth weight, or birth length. These findings suggest no association between paternal MS therapy and negative pregnancy outcomes, however, it is a small sample and further clinical data is needed to make firm recommendations.

A number of Pregnancy Registries are currently collecting Australian data on exposure to MS therapies during pregnancy. These include registries for women taking Fingolimod, and Tecfidera, with another registry currently being established for the newly TGA-approved Alemtuzumab. These registries will publish results of their findings as they become available, and are a vital means of monitoring outcomes for women receiving these medications.

Individuals with MS who are considering pregnancy should discuss their treatment options with their neurologist.

More information and advice on parenting, pregnancy and MS can be found here or by contacting your state MS Society – you can find their contact details here.