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MS and pregnancy

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MS and pregnancy

MS is most often diagnosed between the ages of 20 and 40, when many people may be thinking of having a family. In this article Janice from the MS Trust information team explains what you might have to think about if you have MS and you’re considering having a baby.

Planning for Pregnancy

What’s the risk of MS developing in children?

MS is not hereditary. The majority of people who develop MS have no previous family history of the condition. However, having a relative with MS increases the risk of developing MS. In the UK, the risk of developing MS in your lifetime is about 1 in 330. Family studies have found that if a parent has MS, the risk of the child developing MS is about 1 in 40.

Having a particular combination of genes may make it more likely that someone will go on to develop MS but this in itself doesn’t cause the condition. It is believed that other environmental factors trigger the body to react in a way that starts the development of MS. Some of the factors that are being investigated include infections, low levels of sunlight (and hence vitamin D) and smoking.

Does MS affect fertility?

MS does not directly affect fertility but symptoms such as a fatigue, spasticity or erectile dysfunction could have an impact. Difficulties can often be resolved with support from your partner and advice from health professionals. The MS Trust books Sex and MS: a guide for men and Sex and MS: a guide for women look at how MS can affect sex and give positive and practical solutions.

In the general population, about 1 in 10 couples may have difficulty conceiving so it’s possible that a couple where one partner has MS may have fertility problems that have nothing to do with MS. Research has suggested that some treatments for infertility can increase MS activity, such as relapses, but it is not known if this is a direct effect on MS or indirectly caused by the emotional and physical stress of treatment.

Should I stop taking medicines while trying to conceive?

General medical advice is to avoid drug treatments as far as possible when planning to become pregnant, during pregnancy and when breastfeeding. For both men and women with MS this will mean reviewing the medicines you are taking with your GP and MS team and weighing up the benefits and risks of stopping, continuing or switching to an alternative treatment.
There is little information about pregnancy outcomes if fathers are receiving treatment. A recent study reported that birth weight and duration of pregnancy were not affected when would-be fathers were taking beta interferon drugs or glatiramer acetate around the time of conception.

It is generally recommended that women taking one of the disease modifying therapies should stop taking the drugs three months before trying to conceive but it’s important to discuss this with your MS team. For some women, the benefits of remaining on a treatment may outweigh the risks. Teriflunomide (Aubagio), a new tablet treatment for relapsing remitting MS, remains in the blood for up to two years. Women wishing to become pregnant need to stop taking the drug well ahead of starting a family, although safe blood levels can be reached more rapidly by taking certain medicines.

If you become pregnant while taking medication it is important to contact your MS nurse or neurologist as soon as possible. You can then consider how best to stop medication as some drugs need to be reduced gradually to prevent unpleasant withdrawal symptoms for both mother and baby.

During pregnancy

Will MS affect my pregnancy?

For most women, MS does not make any significant difference to their pregnancy. A woman with MS is no more likely to experience complications of pregnancy, stillbirth or birth defects than a woman who does not have MS.

Will pregnancy affect my MS?

A woman with MS is less likely to have a relapse during pregnancy, particularly during the last three months. The risk of relapse increases in the six months after the birth. This is thought to be due to changes in the levels of hormones, particularly oestrogen, during and after pregnancy.

Pregnancy has no effect on MS in the long-term and it does not hasten progression. After the period of higher risk, the number of relapses will return to the pre-pregnancy level. There is not enough data on pregnancy in women with progressive MS to give an accurate indication of its effect on this type of MS.

Will pregnancy affect my MS symptoms?

Many women with MS feel well during pregnancy, however, some MS symptoms may become more pronounced. Hormonal changes, heat sensitivity, difficulty sleeping and carrying the extra weight during later stages of pregnancy will add to MS fatigue. You might find that you need to go to the loo more often and with less warning because of pressure on the bladder from the baby. Any suspected urinary tract infections should be investigated and treated promptly. In late pregnancy, the increasing weight of the baby and changes in posture may make walking more difficult; gentle exercise such as swimming or yoga may help.

Can I take medicines during pregnancy?

All mums are discouraged from taking medicines during pregnancy if possible. A number of medications for MS, both disease modifying drugs and those for individual symptoms, are not recommended for use during pregnancy or when breastfeeding. There may be alternative drugs which are considered safer so talk to your MS team, midwife or GP.

Further reading

The MS Trust publishes a factsheet on pregnancy.

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