A pregnant women sitting in a wheat field with her hands on her stomach

6 things to know about pregnancy and MS

People are often diagnosed with MS during their 20s and 30s, at the age when some may be thinking about starting a family. This can understandably raise lots of questions about pregnancy and MS.

We take a look at the latest research to answer some of those questions.

1. Will pregnancy have any long-term effects on my MS?

A paper published last week in Australia looked at research on the long-term effects of pregnancy on MS. They concluded that becoming pregnant when you have MS doesn’t have any negative effects on how your MS progresses in the long term.

The most recent study followed women with relapsing MS for over ten years. It found evidence of a protective effect of pregnancy against disability progression – meaning women who had been pregnant found their MS symptoms didn't get worse as quickly. But more research is needed to confirm this finding.

2. Does pregnancy affect my risk of developing MS?

The Australian researchers found little evidence that pregnancy increases the risk of being diagnosed with MS. But we don't have enough evidence yet to say whether pregnancy can actually delay the onset of MS.

Some studies have shown that women with MS may be less likely to have children and women with more children may be less likely to develop signs of MS. But this doesn't prove pregnancy can stop you from developing MS - women with and without MS choose not to become pregnant for many reasons. And an equal number of studies have found no effect of pregnancy on the onset of MS.

3. Does being pregnant affect relapses?

We already know women with MS experience fewer relapses during pregnancy, particularly during the third trimester. And in the three months after giving birth, around a third of women experience relapses at a higher rate than before they became pregnant.

But recent research suggests if you compare the entire year before pregnancy with the entire year after the birth, there's no overall difference in relapses.

4. Why can pregnancy affect MS?

We don't really know yet. Some researchers think it could be related to hormones like oestrogen and progesterone. During pregnancy, the levels of these hormones change dramatically, which may impact the immune system. We're currently funding a project at the University of Oxford to find out more about why pregnancy affects MS.

5. Can I take my MS medication while pregnant?

Researchers agree it’s important for people with MS to start treatment as soon as possible after their diagnosis. And new UK guidelines recommend women with MS should not delay starting treatment, even if they want to become pregnant in the future.

They also recommend women who become pregnant don't immediately stop taking their medication without a discussion with their neurologist or nurse. Some women with very active MS may want to continue treatment during their pregnancy, while others might want to temporarily stop treatment. The guidelines specify which treatments are safe to take while pregnant (such as copaxone) and which are not. But talk to a clinician before making any changes to your treatment.

6. Should I take vitamin D supplements while pregnant?

We know there’s a link between low levels of vitamin D and MS. We don't yet know if taking vitamin D supplements could help manage or prevent MS, but there's no evidence to suggest taking an appropriate dose of vitamin D is harmful during pregnancy.

So the new guidelines recommend women with MS who are pregnant or planning to become pregnant should take a vitamin D supplement.