Balancing Act: MS Care for Women Considering Pregnancy

Medscape

14-07-2025

This transcript has been edited for clarity.
My name is Dr Patricia K. Coyle. I'm professor of neurology and director of the Stony Brook Multiple Sclerosis Comprehensive Care Center at Stony Brook University in Long Island, New York. I'm going to be talking about the treatment of women with multiple sclerosis (MS) from the ages of 18-40 years.
Now, that really defines the prototypic MS patient— a young woman of childbearing age. Pregnancy is a key issue. In fact, expert consensus and treatment guidelines indicate that it's mandated to discuss family planning in appropriate, newly diagnosed and diagnosed MS individuals. That's very, very important. ­
The healthcare provider, in discussing family planning, should indicate to the prototypic patient that pregnancy in MS is not considered a high-risk pregnancy. In fact, MS has very little impact on pregnancy. There is no negative impact. Fertility is not affected. There's no increase in spontaneous abortions. There's no increase in birth defects. You can do any sort of anesthesia or delivery. MS is really not a key factor in that.
Now, one of the things that we do want is a planned pregnancy. We don't want a surprise pregnancy in someone with MS where we haven't thought things out. That should be discussed with the individual.
In addition, it's interesting that the majority of pregnant women [in studies] have relapsing MS and do not have any significant disability. We can speak very confidently about what happens in relapsing MS with little-to-no disability with regard to pregnancy, but there's a lack in understanding of more disabled MS individuals and particularly progressive MS. In fact, in pregnancy cohorts, 87%-97% are relapsing MS, not progressive. We really need to have more studies in progressive MS and more disabled [individuals with] MS.
Often when we're making the diagnosis of MS, that young individual, when we discuss family planning, may really say that they want to plan to have a child right away. Well, expert consensus indicates that we should counsel against that. In fact, expert consensus says that the best pathway in a newly diagnosed MS individual is to treat them for at least 1-2 years in more active or more concerning MS before the planned pregnancy occurs.
Why is that? Data are accumulating, showing that there's a window of opportunity early in the MS disease process to optimally control the damage process. You want to treat early, you don't want patients to wait a couple of years as they try to get pregnant and have a child. They would be better off investing in controlling their MS disease process and then electively going ahead with the pregnancy.
What would we counsel in the pre-pregnancy period? First, we need to know about disease activity. There was a famous PRIMS study published in the late 1990s that mapped the annualized relapse rate in French women, largely relapsing MS, and they found it was stable in the pre-pregnancy period. It went down during pregnancy, went further down so that the third trimester had the lowest relapse rate, and then temporarily rebounded after giving birth for a several-month period before ultimately settling down to the pre-pregnancy baseline.
Now, why is that? Well, there are immune changes and hormonal changes during pregnancy that could be considered treatments for MS disease activity. You see the disease activity go down during pregnancy. There's really an immune tolerance going on [whereby the mother doesn't attack] the foreign fetus. There's a switch from T helper 1 cytokines, which would enhance cell-mediated immunity, which is more prominent in MS, to T helper 2, where you have more humoral antibody immunity that's favorable to MS. Actually, MS disease activity goes down during the pregnancy.
If we're going to have planned pregnancy, we have to discuss contraception. Any contraception can be used in MS, but there should be a discussion in family planning around what the patient is doing to avoid becoming pregnant.
We should put a word in to our patients for long-acting, reversible contraception, which is clearly the most effective. The failure rate is less than 1%. This is using an [intrauterine device] or an implantable rod that is the most effective contraception, and we should actually speak favorably about that to our patients.
Another issue is genetics. Many patients will ask, 'Can I pass MS onto my child?' Some may not ask that, but it's a worry for almost everybody. That should be formally discussed. We know there are about 233 or more genes that control risk susceptibility, and then there are probably disease severity genes and disease protection genes. You don't have any gene that can pass on MS. MS is not considered an inherited disease, so that's important to emphasize to individuals with MS.
DMT Management
'What about disease modifying therapy (DMT) washouts as a person is preparing for their pregnancy? What DMTs do not need to be washed out?' With glatiramer acetate (GA) and interferon beta, there have been thousands of human pregnancy exposures and no negative data. They need no washout. They can be stopped once the person documents that they're pregnant.
By expert consensus, it's the same with the fumarates. The half-life of these agents is an hour or less. It's washed out within a day, and there are no human pregnancy data suggesting harm from the fumarates. By expert consensus, it's accepted that you would take a fumarate until you got pregnant and then discontinue it.
Most recently, the anti-CD20 agents— at least the ones that we have a long history with, such as ocrelizumab, ofatumumab, and rituximab— the Association of British Neurologists in the United Kingdom has published that they believe that you could try to get pregnant immediately after an anti-CD20 infusion. [The guidelines also recommended that women taking ocrelizumab should preferably wait 3 months before trying to conceive.]
Why is that the drug labels continue to indicate waiting 6 months? Well, it's very hard to change labels. It takes a great deal of time and effort to do that. An anti-CD20 is an immunoglobulin G antibody. This is not a toxic chemical. It's also passed by the placenta, but the half-life is such that if you were to stop the anti-CD20 at the time of pregnancy, it would be largely washed out before there would be any concern about exposure of the fetus. Really, you don't need to wash out the anti-CD20s, and I explain that to patients.
What about pregnancy counseling? Could you use a DMT during pregnancy? It's accepted. GA, yes, there are several hundred cases. Interferon beta, yes, but many people would prefer not to be on a disease-modifying therapy that they might not need.
In addition, believe it or not, natalizumab is typically used during pregnancy. Why? Well, because stopping it can result in rebound relapses in a pregnant individual, which leaves them with disability. It's very common to continue using extended dosing of the natalizumab every 6 weeks, up to about weeks 30-34, then discontinuing it and arranging to have the baby delivered by 40 weeks.
Suppose there's a rare relapse during pregnancy. Can you do an MRI scan? Absolutely. MRIs are safe during pregnancy. We don't want you to use gadolinium-based contrast agents. The fetus can be exposed to gadolinium, so you would not use gadolinium unless it was absolutely vital to the medical question that you were asking.
Could you treat a relapse during pregnancy? Yes, you could use steroids. You would certainly not use dexamethasone. You would use methylprednisolone or prednisone, and you would use it short term, the typical treatment for an acute relapse. Some people might not like to use that in the first trimester. There's old literature that suggests an increased risk of cleft lip or palate, but the newer data don't suggest that that is a real risk. Depending on the severity of the relapse, you could go ahead and use steroids as necessary.
What about postpartum counseling? First of all, we have to counsel that there's an increased risk of MS activity and breakthrough relapses in MRI scans in the several months after they deliver the baby. The World Health Organization has recommended breastfeeding for 6 months after giving birth. It appears that breastfeeding is somewhat protective, that MS disease activity goes down with breastfeeding, and it seems as though exclusive breastfeeding is more important.
Do you want to know what the good news is? Monoclonal antibodies can be used in breastfeeding individuals, so you can reinstitute the monoclonal antibody DMT without concern, and certainly GA and interferon beta can be resumed. You have very little detectable DMT in the breast milk and the baby's gut will 'chew it up' anyway. The only DMTs that you don't want to use in breastfeeding are the oral agents because there's not enough data about the exposure there.
MS and Fertility Issues
Now let me move to one final point. I want to speak about fertility issues, assisted reproduction technology and in vitro fertilization (IVF).
I think every neurologist should be aware of oocyte cryopreservation. Women are born with about 1-2 million eggs. By puberty, they have 300,000 eggs left. By menopause, there are [a limited number of] eggs left and the eggs age. You can collect eggs — it should be done before the age of 37 — and cryopreserve them for a later pregnancy if that is a concern.
I finally want to make a point about how dependent we are on getting new information so that we can give the latest updates when counseling our MS individuals. There were several, a total of five, small-scale studies over several years that indicated that MS individuals who went through IVF and failed to get pregnant had breakthrough MS activity for about a 3-month period. They were very small-scale studies, but we actually counseled patients about this.
In the last few years, we've had major studies with much larger numbers of MS individuals who went through IVF, and it turns out that was false. They could not document any increase in relapses whatsoever. In general, there was a tendency to maintain their disease-modifying therapy right up to, and even through, the IVF technique. Therefore, we've changed our counseling. It turned out, in studies with a larger number of participants, IVF is quite safe for MS individuals.
I want to thank you very much for listening.