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Multiple sclerosis usually does not prevent a woman from becoming pregnant, carrying a pregnancy, or giving birth to a healthy child. The modern approach is not to stop treatment automatically for one or two years, but to choose a safe strategy for disease control in advance. Some treatments can be continued until pregnancy is confirmed, and selected therapies can also be used during pregnancy. In addition, several MS treatments are compatible with breastfeeding, so after delivery it is not always necessary to choose between breastfeeding and treating MS.
Key point: pregnancy in MS should now be planned together with the treatment strategy.
For a woman with stable MS, observation during pregnancy may be sufficient. With highly active disease, however, a prolonged treatment interruption may lead to relapses and accumulation of neurological disability. This is particularly important with natalizumab and S1P modulators, especially fingolimod.
In the vast majority of cases, yes. Multiple sclerosis itself is not a contraindication to pregnancy, vaginal delivery, or breastfeeding. MS is also not considered a disease that by itself substantially increases the risk of congenital malformations.
Pregnancy usually does not lead to long-term worsening of MS either. Individual risk, however, depends on disease activity before pregnancy, the degree of neurological disability, and — particularly in the modern treatment era — the disease-modifying therapy being used.
The question today is therefore not “is pregnancy allowed in MS?” but rather: when is the best time to plan pregnancy, and what treatment strategy should be used before conception, during pregnancy, and after delivery?
Pregnancy planning should ideally begin before contraception is stopped. This is especially important in active MS and when the patient is receiving a treatment that may be followed by rapid disease reactivation after withdrawal.
Clinicians usually assess:
If MRI has not been performed for a long time or there have been signs of disease activity, an MRI before pregnancy may be useful as a baseline for later comparison. Not every woman needs a special “pre-pregnancy MRI”, but it is often helpful when treatment is being changed or disease stability is uncertain.
There is no universal rule that “MS must be quiet for two years before pregnancy”. The important issue is to understand the current level of disease activity and to have a treatment plan in place in advance.
Multiple sclerosis itself usually does not cause a major reduction in female fertility. Women with MS can conceive naturally and, when necessary, use assisted reproductive technologies.
Early small studies raised concerns that hormonal stimulation for IVF might increase relapse risk. Later data have been much more reassuring, particularly with modern reproductive protocols and when adequate MS control is maintained.
If IVF is planned, MS treatment should ideally be discussed with the neurologist before hormonal stimulation begins. It is particularly important not to stop an effective treatment too early: several untreated months before an IVF attempt may be substantially more dangerous than the assisted reproduction procedure itself.
This is especially relevant after natalizumab and S1P modulators. In these situations, the neurologist and fertility specialist should coordinate the timing of treatment withdrawal or switching, stimulation, and embryo transfer.
Pregnancy changes immune function. The classic PRIMS study showed that relapse rates fall during pregnancy, particularly in the third trimester. After delivery, this protective effect disappears and relapse risk temporarily increases during the first postpartum months.
However, these data were obtained in an era when highly effective DMTs were barely available. Today we know that the course of MS during pregnancy depends not only on pregnancy itself, but also on which treatment the woman received beforehand and how it was discontinued.
If the disease was stable and the treatment can be stopped safely or has a prolonged effect, pregnancy often proceeds without relapses.
A very different situation may occur after withdrawal of treatments whose effects wear off quickly. After fingolimod or natalizumab, MS activity may return during pregnancy, sometimes severely.
The statement that “pregnancy protects against multiple sclerosis” is therefore only partly true. Physiological suppression of inflammatory activity does occur, but it may not be sufficient to compensate for loss of effect from a highly effective therapy.
The table below provides a practical overview of major DMTs. It is not an instruction for stopping treatment without medical advice: recommendations and national prescribing information may differ, and the strategy depends on disease activity.
| Treatment | Until pregnancy is confirmed | During pregnancy | Breastfeeding | Key point |
|---|---|---|---|---|
| Interferon beta | Can be continued | Can be used if needed | Compatible | A large amount of pregnancy safety data is available. Current recommendations allow treatment to continue during pregnancy when needed for disease control. |
| Glatiramer acetate | Can be continued | Can be used if needed | Compatible | One of the best-studied MS treatments in pregnancy and lactation. |
| Dimethyl fumarate | Until a positive pregnancy test | Usually stopped | Less evidence | Current observational data do not show an increased risk of congenital anomalies after early exposure. Its short half-life means that a long washout is unnecessary. |
| Teriflunomide | Not recommended | Not used | Not used | In an unplanned pregnancy, the drug is stopped and an accelerated elimination procedure with cholestyramine or activated charcoal is performed according to the established regimen. |
| S1P modulators fingolimod, siponimod, ozanimod, ponesimod | Advance planning required | Not used | Not used | The main problem is not only potential fetal risk but also the possibility of marked MS reactivation after withdrawal, especially after fingolimod. |
| Natalizumab | May be continued | Possible in active MS | Compatible | In highly active disease, stopping treatment may be more dangerous than continuing it. Individual extended-interval strategies are used. |
| Ocrelizumab | Pre-pregnancy strategy possible | Usually not administered | Compatible according to current evidence | Its prolonged biological effect after infusion may allow MS control during much of pregnancy without dosing during the second or third trimester. |
| Ofatumumab | Until a positive pregnancy test* | Usually stopped | Compatible according to current evidence | ABN 2026 guidance allows anti-CD20 therapy to continue until pregnancy is confirmed. Specific evidence for ofatumumab is still more limited than for ocrelizumab. |
| Ublituximab | Based on anti-CD20 principles | Limited data | Based on class data | Direct pregnancy data remain much more limited, so decisions depend particularly strongly on the individual situation. |
| Cladribine | Conception 6 months after a treatment course | Not used | Not during dosing | Cladribine is attractive in pregnancy planning because treatment effects may persist after the dosing course has ended, without continuous drug exposure. |
| Alemtuzumab | After the required waiting period | Usually not used | Individual decision | In addition to the drug itself, mandatory laboratory monitoring must continue, including thyroid-function monitoring. |
* For anti-CD20 therapies, increasingly permissive expert recommendations may differ from the official prescribing information of individual products in different countries. The exact pregnancy-planning strategy should therefore be individualized.
This is one of the situations that causes patients the greatest anxiety. Fingolimod is not recommended during pregnancy, and when pregnancy is planned in advance it is usually discontinued before conception.
However, accidental fingolimod exposure in the first weeks of pregnancy does not mean that congenital malformations will inevitably occur and is not, by itself, an automatic indication for termination of pregnancy.
Published registry and observational data have been considerably more reassuring than might have been expected from preclinical findings. In one large analysis, the rate of major congenital anomalies among live births after fingolimod exposure was approximately 2.7–4.0% across different datasets and was not statistically different from the range observed in the general population. No characteristic pattern of fingolimod-associated malformations was identified.
In a small prospective ENTIS study, the rate of major congenital anomalies was 4.8% after fingolimod and 2.3% after interferon beta. The difference was not statistically convincing because of the small number of pregnancies, so a modest increase in risk cannot be completely excluded.
Practical approach to an unplanned pregnancy:
Fingolimod is discontinued, but the woman should not conclude that pregnancy termination is required solely because of early exposure. Consultation with a maternal-fetal medicine specialist and detailed expert fetal ultrasound are usually recommended.
At the same time, the neurologist must address a second, equally important problem: what happens to MS after fingolimod withdrawal. In the German registry, relapses occurred in approximately one third of women during pregnancy and in almost half during the first year after delivery. In a small proportion of patients, a severe relapse left persistent worsening.
For this reason, a woman who plans pregnancy while taking fingolimod is now often advised not simply to stop the drug two months beforehand, but to move to another treatment strategy before discontinuation.
Anti-CD20 therapy is one of the clearest examples of how pregnancy management in MS has changed in recent years.
Ocrelizumab is administered intermittently, but its biological effect lasts much longer than the drug remains in the circulation. In some patients this allows an infusion before conception and prolonged disease control during a substantial part of pregnancy without additional dosing.
Placental physiology is also important. Active transfer of maternal IgG across the placenta is minimal very early in pregnancy and increases later. Exposure shortly before conception is therefore fundamentally different from anti-CD20 administration in the second or third trimester.
A large analysis of 3,244 reported pregnancies after ocrelizumab treatment found no increase in spontaneous abortion, preterm birth or major congenital anomalies. Among live births, major anomalies were reported in approximately 2.1% of exposed and 1.9% of non-exposed pregnancies.
The situation is somewhat different because of monthly subcutaneous dosing. Older practical recommendations often followed the product label and required a relatively long period of contraception after treatment was stopped.
The 2026 Association of British Neurologists consensus took a more practical approach: anti-CD20 therapy, including ofatumumab, may be continued until the first positive pregnancy test. After pregnancy is confirmed, treatment is usually stopped in MS.
Direct data on ofatumumab are still less extensive than those for ocrelizumab. In practice, clinicians therefore take into account current expert recommendations, the official product information in the country of treatment, and the individual risk of MS activity.
A positive pregnancy test during MS treatment should almost never lead to a panic decision. Risks differ greatly between treatments.
Important questions include:
Early exposure to interferon beta, glatiramer acetate, dimethyl fumarate or ocrelizumab is generally not considered an indication for pregnancy termination.
After fingolimod exposure, closer obstetric follow-up is appropriate, but accidental early exposure still does not mean that an adverse outcome is inevitable.
Teriflunomide is different: the drug should be stopped and an accelerated elimination procedure performed.
After natalizumab, it is particularly important not only to assess fetal exposure but also to avoid disease rebound caused by an unnecessarily prolonged treatment interruption.
There are still many unnecessary restrictions surrounding MRI during pregnancy.
Yes. MRI does not use ionizing radiation and, according to current recommendations, is not contraindicated in the first, second or third trimester.
If the woman is clinically well and MS is stable, routine MRI simply because pregnancy has occurred is usually unnecessary.
However, if a new neurological symptom appears and the result could change management, MRI should not be postponed until after delivery solely because of pregnancy.
Gadolinium is not used routinely during pregnancy. It crosses the placenta, so the usual approach when MS activity is suspected is MRI without contrast.
This is not an absolute prohibition on all contrast-enhanced MRI. In a rare clinical situation where critical diagnostic information cannot be obtained without gadolinium and the result would affect an important treatment decision for the mother, contrast may be considered individually.
For routine assessment of MS activity, this situation is uncommon.
After delivery, the situation is very different.
Less than 0.04% of the maternal gadolinium contrast dose is excreted into breast milk during the first 24 hours. Of the amount that reaches the infant’s gastrointestinal tract, less than 1% is absorbed. The resulting systemic infant dose is therefore less than 0.0004% of the maternal dose.
For this reason, the American College of Radiology considers that breastfeeding can continue without interruption after gadolinium administration.
European ESUR guidance also takes the type of contrast agent into account. With modern macrocyclic agents such as gadobutrol, gadoterate or gadoteridol, interruption of breastfeeding is not required.
For some older linear gadolinium agents with less stable chelation, a 24-hour interruption with milk expression was historically recommended. Many of these agents are now used much less often or are restricted.
If a woman wishes to eliminate even the minimal theoretical exposure, she may voluntarily pause breastfeeding for 12–24 hours after contrast administration. There is no medical reason to interrupt breastfeeding for more than 24 hours.
Before the scan, it is therefore more useful not simply to ask “is contrast MRI allowed during breastfeeding?”, but to ask the radiologist for the exact name of the gadolinium agent.
Not every worsening of symptoms during pregnancy represents a new relapse. Urinary tract infection, fever, sleep deprivation, overheating, anemia and marked fatigue can temporarily worsen pre-existing MS symptoms.
The first step is therefore to exclude a pseudo-relapse, particularly infection.
If a new or clearly worsened neurological deficit lasts for more than 24 hours and cannot be explained by infection or fever, the clinician assesses the likelihood of a true relapse.
A mild sensory episode with little effect on daily function does not always require treatment.
If the relapse affects vision, walking, limb strength or another important function, high-dose methylprednisolone pulse therapy can be used during pregnancy. Current recommendations allow treatment of clinically significant relapses regardless of trimester when the expected benefit outweighs the risk.
For a very severe relapse with inadequate response to corticosteroids, plasma exchange may be used.
Multiple sclerosis itself is not an indication for cesarean delivery. For most women, the mode of delivery is determined by standard obstetric indications.
MS is also not a contraindication to epidural or spinal anesthesia. There is no convincing evidence that epidural anesthesia increases postpartum relapse risk or worsens the disease course.
Individual planning is required in women with marked disability, substantial motor impairment, severe spasticity, respiratory dysfunction or other conditions that may complicate delivery.
After delivery, the immunological changes of pregnancy rapidly disappear. At the same time, the woman may already have had a long treatment interruption that began before conception. The combination of these factors creates postpartum risk.
Particularly careful postpartum planning is needed in women:
The postpartum treatment plan is therefore best decided during pregnancy rather than after discharge from the maternity unit.
A follow-up MRI soon after delivery may sometimes be reasonable, particularly when treatment has been interrupted for a long time or disease activity risk is high.
Modern management increasingly avoids treating breastfeeding and MS therapy as mutually exclusive.
Women with stable disease may be able to breastfeed for longer without immediately escalating therapy. When relapse risk is high, it is usually better to restart effective treatment early and, whenever possible, choose a therapy compatible with breastfeeding.
Observational studies suggest that exclusive breastfeeding may be associated with a lower postpartum relapse risk. However, this effect should not be overestimated: breastfeeding is not a treatment for MS and does not replace disease-modifying therapy.
The most convincing evidence is available for interferon beta and glatiramer acetate.
Natalizumab enters breast milk in small amounts, but intestinal absorption by the infant is extremely low. Current recommendations allow breastfeeding to continue when natalizumab treatment is needed.
Important new evidence has also emerged for anti-CD20 monoclonal antibodies. Ocrelizumab is found in breast milk only in minimal amounts, and systemic infant exposure is extremely low.
A dedicated 2025 study examined breastfeeding during ofatumumab treatment. No increase in infections, hospitalizations or developmental delay was observed in the infants; among infants in whom B-cell counts were measured, the counts were normal.
A larger 2026 study compared 183 breastfed infants whose mothers received monoclonal antibodies with 183 unexposed infants. Rates of developmental delay, serious infections, antibiotic treatment and hospitalization were not meaningfully different.
These data are especially important for women with active MS: restarting effective treatment after delivery does not always require stopping breastfeeding.
S1P modulators, including fingolimod, are not recommended during breastfeeding: they are small molecules that may enter milk and be absorbed by the infant.
Teriflunomide is also not used during breastfeeding. With cladribine, breastfeeding must be interrupted around the dosing period.
Evidence for dimethyl fumarate remains limited. Concentrations of its active metabolite in milk are low and small case series have not identified adverse outcomes, but decisions are still usually individualized.
If methylprednisolone pulse therapy is required after delivery, breastfeeding usually does not need to be stopped completely.
To reduce infant exposure further, the mother can feed immediately before the infusion and leave the longest convenient interval before the next feed. Current recommendations do not require routine pumping and discarding of milk.
This concerns primarily in-utero exposure to selected monoclonal antibodies rather than exposure through breast milk.
If an anti-CD20 agent was administered in the second or third trimester, the antibody may cross the placenta and temporarily reduce the infant’s B-cell count. In this situation, CD19+ B cells should preferably be checked before live vaccines are given.
If B-cell counts are low, live vaccination is postponed until B-cell recovery. Inactivated vaccines are generally continued according to the usual schedule.
After natalizumab exposure late in pregnancy, anemia or thrombocytopenia may occasionally be found in the newborn. The pediatrician should therefore know about the exposure, and a complete blood count after birth may be appropriate.
Multiple sclerosis is not a disease that is directly inherited from parent to child. What is inherited is a predisposition involving many genetic factors.
If one parent has MS, the absolute risk for the child remains low and is generally estimated at only a few percent. In other words, the great majority of children born to a mother or father with MS will never develop multiple sclerosis.
There is no routine genetic test during pregnancy that can determine whether a child will develop MS in the future.
No. It depends on the treatment. Interferon beta and glatiramer acetate can be continued; dimethyl fumarate and, according to ABN 2026 guidance, anti-CD20 therapy can be used until pregnancy is confirmed. S1P modulators, cladribine and some other therapies require a pre-planned strategy.
No. Fingolimod is stopped and the pregnancy is followed more closely, but published data do not show an inevitable high risk of congenital malformations. Maternal-fetal medicine consultation and detailed expert ultrasound are recommended. At the same time, the neurologist should assess the risk of MS reactivation after treatment withdrawal.
Updated UK guidance from 2026 allows anti-CD20 therapy, including ofatumumab, to continue until the first positive pregnancy test. Official product information may be more conservative, so the exact strategy should be agreed with the treating neurologist.
Yes. MRI without contrast is not contraindicated in any trimester. It should be performed when the result is clinically important for diagnosis or treatment decisions.
Gadolinium is generally avoided during pregnancy. In rare situations it may be used when critical diagnostic information cannot otherwise be obtained.
After modern macrocyclic gadolinium agents, breastfeeding does not need to be interrupted. If an older higher-risk linear agent is used, or if the mother wishes to avoid even minimal exposure, a pause of up to 24 hours may be discussed. A longer interruption is generally unnecessary.
Current evidence supports this as an acceptable strategy. Ofatumumab enters breast milk in very small amounts and infant gastrointestinal absorption is minimal. Published observations have not shown adverse effects on development, infection rates or infant B-cell counts.
No. In the absence of other obstetric indications, a woman with MS can deliver vaginally. Epidural anesthesia is also permitted.
Advance planning is particularly important when a woman receives natalizumab, fingolimod or another S1P modulator, ocrelizumab, ofatumumab, cladribine or another highly effective therapy.
Recent relapses, new MRI lesions, highly active MS and previous episodes of marked worsening after treatment withdrawal also require special attention.
A consultation is an opportunity to make a plan for the entire period: pre-conception preparation, therapy during pregnancy, management of a possible relapse, MRI monitoring, timing of postpartum DMT restart and compatibility of the chosen treatment with breastfeeding.
Consult Dr. Lidiia PrakhovaThis page is intended for educational purposes and does not replace an individualized decision by a neurologist and obstetrician-gynecologist. Recommendations for specific treatments may differ by country and according to current prescribing information.