Multiple Sclerosis and Pregnancy: Every Stage Explained by an MS Specialist

One of the first questions many people ask after a multiple sclerosis diagnosis is whether they can still have children. The answer is yes — most patients with MS have healthy pregnancies and healthy babies. MS does not need to stand between you and motherhood. What it does require is planning, and that's exactly what this guide is designed to help you do.

In my practice, pregnancy planning is one of the most common and most important conversations I have with my MS patients. The questions are understandable: Will my medications hurt the baby? Will pregnancy make my MS worse? Can I breastfeed? These are the questions I'll answer here, drawing on the latest evidence and my experience as an MS specialist.

How Pregnancy Affects MS

One of the most reassuring findings in MS research is that pregnancy is naturally protective against relapses. During pregnancy, your immune system shifts to protect the developing baby, and this shift also dampens the autoimmune activity that drives neuroinflammation in MS.

Here's what the data consistently shows:

• First trimester: Relapse rates begin to decline compared to the year before pregnancy
• Second trimester: Relapse rates drop further
• Third trimester: Relapse rates fall by approximately 70 percent compared to pre-pregnancy levels
• Postpartum period: Relapse risk increases in the first three to six months after delivery, then returns to pre-pregnancy baseline

This pattern has been confirmed in multiple large studies over the past three decades. The third trimester is essentially a period of natural immune suppression, which is good news for MS.

The postpartum period, however, requires careful planning. About 20 to 30 percent of women experience a relapse in the first three months after delivery, particularly if they were not on a disease-modifying therapy before or during pregnancy. This is why I work with my patients to have a clear plan for restarting medication after delivery. For more on recognizing and managing relapses, see our guide on what to do during an MS relapse.

Fertility and MS

MS itself does not affect fertility. Women with MS can conceive at the same rate as women without the condition. However, there are a few important nuances:

• Some MS medications can affect fertility or harm a developing fetus. This is the primary reason why preconception planning is essential.
• Sexual dysfunction related to MS (fatigue, spasticity, sensory changes) can indirectly affect conception, but these are manageable with your care team.
• Assisted reproductive technology (IVF, hormonal stimulation) is safe for women with MS, though some studies suggest that hormonal treatments used in IVF may slightly increase relapse risk. Discuss this with your neurologist and fertility specialist.
• Stress and fatigue associated with fertility treatments can temporarily worsen MS symptoms, which is not the same as a relapse.

The bottom line: MS should not be a reason to avoid pregnancy. With proper planning, the vast majority of women with MS have uncomplicated pregnancies.

MS Medications and Pregnancy Safety

This is the area that requires the most careful planning. No MS medication is formally FDA-approved for use during pregnancy, but we have decades of data — including pregnancy registries and real-world outcomes — that guide decision-making.

Medications That Must Be Stopped Well Before Conception

Teriflunomide (Aubagio): This oral medication is known to cause birth defects and must be eliminated from the body before conception. Because teriflunomide has a very long half-life (it can remain in the body for up to two years without intervention), an accelerated elimination procedure using cholestyramine or activated charcoal is required. Blood levels must be confirmed undetectable on two separate tests before it is safe to conceive.

Fingolimod (Gilenya), siponimod (Mayzent), ozanimod (Zeposia), ponesimod (Ponvory): The S1P receptor modulators are associated with birth defects and must be stopped several months before conception. Importantly, stopping fingolimod carries a risk of severe rebound disease activity, so this transition must be carefully managed by your neurologist.

Medications With Shorter Washout Periods

Dimethyl fumarate (Tecfidera), diroximel fumarate (Vumerity), monomethyl fumarate (Bafiertam): These oral medications are generally stopped before actively trying to conceive. They have a short half-life and clear the body quickly. Limited pregnancy exposure data has not shown a clear pattern of birth defects, but discontinuation before conception is recommended.

Medications That May Be Continued Closer to Conception

Glatiramer acetate (Copaxone, Glatopa): Glatiramer acetate has the longest track record of pregnancy safety data among all MS medications. It is a large molecule that does not readily cross the placenta. Many neurologists allow patients to continue glatiramer acetate until a positive pregnancy test, and some data supports its use even throughout pregnancy without increased risk.

Anti-CD20 Therapies: Timing Around Conception

The anti-CD20 therapies — ocrelizumab (Ocrevus), ofatumumab (Kesimpta), and ublituximab (Briumvi) — have become some of the most commonly used high-efficacy MS treatments, and their use in pregnancy planning is an active area of research.

These medications work by depleting B cells, and their protective effect on MS lasts well beyond the time the drug is detectable in the body. This creates a unique opportunity for pregnancy planning: a woman can receive her last dose, wait for the drug to clear the body, and still have meaningful disease protection during pregnancy because B-cell repopulation takes time.

I counsel my patients on anti-CD20 therapies to plan the timing of their last infusion carefully. Emerging data from pregnancy registries has been reassuring, with no clear signal of increased birth defects. However, infants exposed to anti-CD20 therapies late in pregnancy can have transient B-cell depletion, which is why timing matters.

Planning Your Pregnancy With MS

The ideal approach is to begin planning at least six to twelve months before you want to conceive. Here's the general framework I use with my patients:

1. Assess disease stability. Ideally, your MS should be well controlled — no recent relapses, stable MRI, no new symptoms — for at least six to twelve months before trying to conceive. The neurofilament light chain blood test can help confirm disease stability before adjusting medications.
2. Review your medication. Based on which therapy you are on, we create a timeline for stopping or transitioning your medication.
3. Optimize your health. Start prenatal vitamins (especially folate), optimize your vitamin D levels, manage any MS symptoms, and address lifestyle factors. Our guides on lifestyle changes for brain health in MS and the best diet for MS cover strategies that also support a healthy pregnancy.
4. Get a baseline MRI. An MRI before conception establishes a reference point that your neurologist can compare to if any questions arise during or after pregnancy.
5. Plan for postpartum. Decide in advance when and how you will restart medication after delivery, and whether you plan to breastfeed.

I help women create a personalized pregnancy timeline that accounts for their specific medication, disease activity, and family planning goals. If you would like expert guidance, consider scheduling a preconception consultation or a telehealth appointment to start the planning process.

During Pregnancy

Monitoring Your MS

Most women with MS have uneventful pregnancies. Routine prenatal care is the same as for any woman. However, a few MS-specific considerations apply:

• Neurological check-ins. I typically see pregnant MS patients once per trimester, or more frequently if there are concerns.
• MRI during pregnancy. MRI without gadolinium contrast is considered generally safe during pregnancy and can be performed only if there is a clinical need. Gadolinium crosses the placenta and is avoided during pregnancy.
• Symptom monitoring. Fatigue, bladder symptoms, and balance changes are common in pregnancy generally and can overlap with MS symptoms. Track any new neurological symptoms and report them to your neurologist.

What to Do If a Relapse Occurs During Pregnancy

Relapses during pregnancy are uncommon, especially in the second and third trimesters, but they can happen. If you experience new neurological symptoms:

• Contact your neurologist promptly
• Mild relapses may be monitored without treatment
• For significant relapses, short courses of corticosteroids (typically methylprednisolone) can be used, especially after the first trimester. Corticosteroids have been used safely in pregnancy for many conditions
• Plasma exchange is available as a second-line option for severe relapses

Delivery and Anesthesia

MS does not dictate how you deliver your baby. Vaginal delivery and cesarean section are both safe. Epidural and spinal anesthesia are generally safe for women with MS — this is a common misconception that persists despite strong evidence to the contrary. Discuss your preferences with your obstetrician and anesthesiologist, and let them know about your MS diagnosis.

The Postpartum Period

The first three to six months after delivery are the highest-risk period for MS relapses. Several factors contribute:

• The immune system shifts back from its pregnancy-protective state
• Sleep deprivation and physical stress of caring for a newborn
• Hormonal changes
• Delay in restarting disease-modifying therapy

In my practice, I discuss the postpartum medication plan during the third trimester so that there is no delay. The goal is to restart therapy as soon as it is safe to do so after delivery, balancing breastfeeding preferences with relapse prevention.

Breastfeeding and MS Medications

Breastfeeding is a deeply personal decision, and women with MS deserve support no matter what they choose. Here's what the evidence tells us:

Exclusive breastfeeding may be protective. Several studies have found that women who exclusively breastfeed (no supplemental formula) for at least two months postpartum have a lower risk of postpartum relapses. The mechanism likely involves continued hormonal suppression of the immune system. However, this protective effect is not guaranteed, and it should not be the sole strategy for relapse prevention in women with active MS.

Medication considerations during breastfeeding: Some MS therapies, particularly larger injectable molecules, have minimal transfer into breast milk and may be compatible with breastfeeding. Others, especially oral medications, are generally not recommended while nursing. The safety profile varies by drug, so this is an important conversation to have with your neurologist well before delivery.

I counsel my patients that the decision to breastfeed, formula-feed, or do a combination is entirely valid. What matters most is that you have a clear plan that balances your desire to breastfeed with the need to manage your MS effectively. No one should feel pressured in either direction.

Long-Term Outlook

The long-term data on MS and pregnancy is reassuring:

• MS does not increase the risk of miscarriage, birth defects (unrelated to medication), premature birth, or low birth weight when medications are appropriately managed
• Pregnancy does not worsen the long-term course of MS. In fact, some studies suggest that women who have been pregnant may have a slightly slower disease progression over decades
• Your child's risk of developing MS is low. Genetics can slightly increase the chance, but MS also requires environmental triggers to develop. The vast majority of children born to a parent with MS never develop the condition
• Having multiple pregnancies is safe. Women who wish to have more than one child can do so with the same careful planning approach

When to See Your MS Specialist

Reach out to your MS neurologist if:

• You are thinking about becoming pregnant in the next year and want to start planning
• You have recently found out you are pregnant and are still taking MS medication
• You are experiencing new neurological symptoms during pregnancy
• You are postpartum and noticing new or worsening symptoms
• You want guidance on breastfeeding and medication decisions
• You were recently diagnosed with MS and have questions about family planning
• You want a second opinion on your pregnancy and MS management plan

At Achilles Neurology Clinic in Beverly Hills, we specialize in helping women with MS navigate every stage of family planning. Pregnancy planning in MS is not something that fits into a rushed fifteen-minute visit. There are medication timelines to map out, breastfeeding decisions to weigh, and a postpartum plan to build. That is why our preconception consultations are structured as extended, unhurried visits where every question gets the attention it deserves. Whether you're just starting to think about pregnancy or already expecting, we're here to help you plan with confidence.

Frequently Asked Questions

Can I get pregnant if I have MS?

Yes. Multiple sclerosis does not affect fertility, and most women with MS can have healthy pregnancies and healthy babies. The key is planning ahead with your neurologist to ensure your medication plan is pregnancy-safe and your disease is well controlled before conception.

Which MS medications are safe during pregnancy?

No MS medication is formally FDA-approved for use during pregnancy. However, glatiramer acetate (Copaxone) has the longest safety track record and is sometimes continued until a positive pregnancy test or even throughout pregnancy. Interferons are generally stopped before conception. Anti-CD20 therapies like ocrelizumab and ofatumumab are timed so that the last dose is given several months before conception, allowing the drug to clear while protective effects continue. Teriflunomide and fingolimod must be stopped well in advance due to specific risks.

Does pregnancy make MS worse?

Pregnancy is actually protective against MS relapses. Relapse rates drop significantly during pregnancy, especially in the third trimester, due to natural immune changes that protect the baby. However, the first three to six months postpartum carry an increased risk of relapse, which is why having a plan to restart medication after delivery is essential.

Will my baby have MS?

While genetics can slightly increase the chance, MS also requires environmental triggers to develop. The overall risk to your child is very low, and the vast majority of children born to a parent with MS never develop the condition.

Can I breastfeed while taking MS medication?

Some women choose to breastfeed without MS medication and restart treatment after weaning. Exclusive breastfeeding may offer some protection against postpartum relapses. For women at higher risk of relapse, certain medications have limited transfer into breast milk and some specialists support restarting them during breastfeeding after careful discussion of risks and benefits.

When should I stop MS medication before getting pregnant?

The timing depends entirely on which medication you are taking. Some therapies can be continued until conception is confirmed, while others need to be stopped weeks or even months in advance. Certain medications also carry a risk of rebound disease activity if discontinued without a plan. Because the details vary so much from drug to drug, this is one of the most important conversations to have with your MS specialist well before you start trying to conceive.

About the Author

Dr. Achillefs Ntranos MD

Board-Certified Neurologist
Achilles Neurology Clinic

Dr. Achillefs Ntranos MD is a board-certified neurologist and MS specialist known for his thorough evaluations and compassionate approach. Originally from Greece, he trained at Johns Hopkins University and Mount Sinai Hospital before founding Achilles Neurology Clinic in Beverly Hills to deliver comprehensive, patient-centered neurological care. He specializes in MS, autoimmune neurology, neuropathy, headaches, and other neurological disorders, blending research-driven insights with personalized treatment plans.

Learn More About Dr. Ntranos(310) 774-7025