Ask the expert: periods, pregnancy, breastfeeding and the menopause

1 May 2024

Women go through hormonal changes during various stages in their life. But how do these changes affect multiple sclerosis? We spoke to consultant neurologist, Ruth Dobson, to understand how periods, pregnancy, fertility treatments, breastfeeding and the menopause affect MS.

Hormones and MS

Do hormones explain why MS is more common in women than men?

Ruth says: MS is almost three times as common in women than men. There must be some reason for this. One of the biggest differences between women and men is their hormones. This drives many physical differences that we see. It makes sense that hormones are implicated, but we don't really know the details of why this is.

In children before they hit puberty, MS is equally common in males and females. After going through puberty and the hormonal changes it brings, the sex difference starts to appear. This suggests that hormones play a part in some way. It’s possible that female hormones may drive inflammation.

We also see that in people who present with progressive MS from the start, the sex difference disappears to quite a large extent. The proportion of men and women affected by progressive MS from onset is much more similar. This is probably something to do with hormonal influences on inflammation, as inflammation is seen to a lesser extent in progressive MS.

Periods and MS

Why do some women’s MS symptoms worsen during their period?

Ruth says: When symptoms are worsening around your period, sometimes it can be due to the change in body temperature around this time of your menstrual cycle. It can also be caused by fluid shifts that occur as part of your menstrual cycle. Women are affected by periods in all kinds of ways that we can't always explain or understand. Different people are vulnerable to hormone fluctuations in different ways. There are some women whose periods aren't responsible for fluctuating symptoms – every woman is individual.

In terms of dealing with worsening symptoms during your period, it's important to find a solution that's right for you. In other neurological conditions where periods affect symptoms, some women find that things improve when they take hormonal contraception that stops periods from happening. Depending on your circumstances, that may be something that can help.

There is an element of trial and error to find what works for you. Sometimes having the knowledge of your cycle and being able to plan around it can help. For instance, if you know you’re going to feel rotten a couple of days each month, you could keep plans to a minimum on those days.

Trying for a baby, including fertility treatments

Should your MS be under control before you try for a baby?

Ruth says: In general, we understand that getting your MS under control, with a disease modifying drug (DMD) if needed, prior to trying to conceive is ideal. But that's got to be balanced against the chances of getting pregnant and conceiving, because for some people they may not have time. It may be that you need to start trying to conceive, because you don’t have time to put things on hold.

The advice given around DMD use depends on your personal situation – your age, how active your MS is, support networks, and what your family plans are at that time. It's difficult to give a short answer to this question, but in general, it's preferable to have your MS under control if you can. If you have time to achieve that before trying to conceive.

There are certain DMDs that are safe to take around conception. There are certain DMDs that your neurologist may advise you to continue into pregnancy. There are others that we would not recommend taking when you're trying to conceive – drugs like Gilenya (fingolimod), for example. Then there are induction therapies where we may advise people not to try to conceive while you're receiving the two years of treatment, but after those two years you can. This might be an appropriate choice for someone who isn’t sure about having children now, but in a couple of years, that's where they want to be in their life. 

If you’re going through fertility treatment, can the hormone medications involved affect your MS?

Ruth says: There's a lot of complexity around fertility treatment, and around the kinds of treatments that are offered. The fertility treatment that might be given for a same sex couple to allow them to get pregnant may be very different from someone who's had years and years of unexplained infertility. Similar to MS treatments, these are constantly evolving.

It's been really reassuring over the past couple of years as there's been a couple of large studies showing that, in contrast to previous work, fertility treatments appear not to increase the risk of MS relapse. This is particularly in people who take a DMD up to the point of embryo transfer or have well-controlled MS up to the point of embryo transfer.

A study in the US looked in detail across a range of fertility treatments, with varying degrees of hormonal manipulation, and saw with all of those that the MS appeared to be unaffected. Those women were mainly treated with a DMD during at least some of their fertility journey.

A French study looked at a very large number of people with MS receiving fertility treatment. They found the relapse rate was completely flat, or even lower, post fertility treatment in the people that had received a DMD in the months prior to fertility treatment.

This research is very reassuring for people. Undergoing fertility treatment is a big thing – it involves a lot of psychological, emotional and physical stress. Adding the worry of controlling MS on top of that is a huge extra thing for someone who’s already going through the stress of fertility treatment.

Pregnancy and birth

What happens if you get pregnant while taking a DMD?

Ruth says: It depends what DMD you’re taking. You shouldn't suddenly stop your DMD. Instead, have a conversation with your neurology team via your MS nurse to discuss that. We know that not every pregnancy is planned. Don’t feel like you're going to get judged for not having discussed it before.

It's important that your views are taken into account. Some people feel very strongly that they wouldn't want to continue treatment with a DMD during pregnancy. It does sometimes require a discussion around whether you should come off everything or whether you should switch to something with proven safety benefit during pregnancy. Some people, on the other hand, feel very strongly that they would never want to come off treatment. This also requires a discussion. Is this treatment safe to continue during pregnancy? Are there ways that we can change treatment schedules to ensure the best safety during your pregnancy? It's about giving you as a person with MS that information to make a decision about what is best for you, together with your neurology team.

Do you need to stop taking symptomatic treatments during pregnancy?

Ruth says: There are a huge number of medications that people with MS might be on. It varies medication by medication. In general terms, what we aim for is the minimum amount of medication during pregnancy. Sometimes when people are planning a pregnancy, they may choose to switch some of their medications, or they may choose to try and reduce them to the minimum amount during pregnancy. If you find yourself unexpectedly pregnant without having thought about it before, it's about discussing each of those medications in turn.

There's some useful information online. There's a website called bumps which gives information about medication use in pregnancy. You can type in the name of your medication, and it will tell you what the evidence is around the use of that medication in pregnancy, including what the risks and the benefits are.

With a lot of the symptomatic medications, the benefits are in terms of how you feel on a day-to-day basis and being able to live your daily life as you wish to do it. There is an element of that that is much more personal about whether you feel this benefit is worth it. It may be that the medication you're taking isn't the right one to continue all the way through your pregnancy. You might have to do a switch. In an ideal world, you do these switches before you get pregnant. If that's not possible, then it's still possible to switch medications during pregnancy. It's not that we say “no, you absolutely can’t take anything”. Rather, “this is the least risky way to approach medication, looking at the amount that you're taking overall.”

Is it safe for women with MS to receive an epidural during labour?

Ruth says: Yes, absolutely. Sometimes people with MS meet concern from obstetric or anaesthetist teams around epidurals and the risk of bringing on a relapse. But we know from very large data that epidurals and spinal anaesthesia are not associated with increased relapse risk in the postpartum period. We know that women with MS are already more likely to have a relapse postpartum (regardless of having an epidural) – that's what drives that worry.

Are there extra considerations for pregnant women with MS when it comes to birth plans?

Ruth says: Think about you and what you want. There are very few birth options that shouldn't be available to you as a woman with MS. It may be that for some people – because of specific physical challenges they experience – there may be some birth options that aren't recommended. But generally, women with MS (particularly with very little disability) should have all birth options available to them, including homebirth and midwife-led unit.

Obstetric teams have experience looking after people with chronic conditions. People with more disability – where they might have difficulty getting into certain positions – should be offered the chance to have a full and frank discussion with the obstetric and midwifery team about the specific challenges that they might face.

The discussion should centre around you as a person and what challenges you might face. Some people who struggle with fatigue might feel they want to go for an assisted birth earlier than they might otherwise do, for example. That should be your choice as a person. There should be discussion around what symptoms you experience with your MS and thinking about your birth plan from that perspective.

The challenge with birth plans is that things don't always go how you want them to. Completely external to MS, people come in with very detailed birth plans and sometimes feel very cheated if things don't go how they wanted them to. It can be helpful to think “this is what I want and how I'd like things to go. But if this happens, and things aren't going how I want them to, what will I do?” Think through some of those options as well. Things don't always go how you plan.


Is it okay to breastfeed when you have MS?

Ruth says: Yes, absolutely. MS shouldn't stop women from breastfeeding. If you have certain disabilities, it may be that you need a bit more help from breastfeeding support services to work out the mechanics of how to hold the baby to achieve successful breastfeeding. Breastfeeding is something you have to learn as a partnership between you and the baby. It's not easy. It doesn't come naturally to most people. Some people, regardless of physical disability, need more help than others. MS isn't a reason not to breastfeed. Don't be afraid to ask for help if that's what you want to do.

Do the hormones involved in breastfeeding protect against relapses?

Ruth says: We understand that exclusive breastfeeding (or exclusive breastfeeding with pumping) provides protection against relapses for at least three months after birth, potentially up to six. It’s slightly time limited to the first bit when the baby's quite young, before they start weaning. It's probably equivalent to a moderate efficacy DMD at best.

Is it safe to breastfeed while taking a DMD?

Ruth says: Neurologists are increasingly comfortable with people breastfeeding on certain medications. If you're somebody with high disease activity and you're keen to breastfeed, then definitely have a conversation with your neurologist. It may be that you can start a breastfeeding-safe DMD in that postpartum period.

In general, there are some DMDs that we’d be completely comfortable with people breastfeeding on, some where it might be a bit more of an individual discussion with your neurologist, and some – particularly those that are not safe during pregnancy – that aren't compatible with breastfeeding.

Menopause and bone health

How can you tell the difference between MS symptoms and menopause symptoms?

Ruth says: Many people find it hard to tell the difference between MS symptoms and menopause symptoms – you’re not alone in that. Symptoms like fatigue, poor sleep, cognitive fog, bladder symptoms and sexual dysfunction are common to both, and can essentially be indistinguishable.

Sometimes we end up doing something pragmatic and treating the symptoms as if they’re being caused by one of these things and seeing what happens. Does it get better? If it doesn't, we can try treating it as if they’re being caused by the other one.

One of the things I would say, particularly if you're female and you’re perimenopausal, is that often menopausal symptoms are easier to treat than MS symptoms. Hormone replacement therapy (HRT) tends to be pretty effective. Whereas, often with some of the symptomatic treatments that we use in MS, they're a bit less effective and don’t always work. If somebody's having other perimenopausal symptoms, I'd be tempted to go in with hormonal therapies first for some of those shared symptoms to see what impact they have.

Generally speaking, HRT is safe in MS. It isn't a reason not to have HRT. It’s best to talk to your GP about hormone treatments and the benefits and risks to you individually.

How can women with MS look after their bone health as they get older?

Ruth says: There is evidence that people with MS are more likely to have fragility fractures (fractures associated with poor bone health) than people without MS. This is probably not just due to weak bones. It's also due to the physical effects of MS, and the increased risk of falls, particularly in people with more advanced MS.

Looking after your bone health is important in MS. It can help to:

  • continue to do weight-bearing exercise where possible (this helps protect your bones)
  • stop smoking
  • make sure you're not drinking too much alcohol
  • seek out bone density (DEXA) scans
  • take bone protective medications (if those are indicated) 
  • consider HRT to help protect bones.

Ruth Dobson is a Consultant Neurologist at Barts Health NHS Trust, London. She is a Professor of Clinical Neurology at the Centre for Preventative Neurology, Wolfson Institute of Population Health, Queen Mary University of London.

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