Multiple Sclerosis (MS) and Pregnancy: What You Should Know

If you have multiple sclerosis (MS), you may be wondering how it could affect your ability to become pregnant and give birth to a healthy baby.

Here’s what experts say about managing MS and pregnancy, including what to discuss with your doctor if you’re considering becoming pregnant.

One of the main considerations for people with MS considering pregnancy is how and when to stop taking medications for MS — known as disease-modifying therapies (DMTs) — while minimizing the risk of an MS relapse, or flare, during or after pregnancy.

“We don’t consider any of the currently available therapies safe for use during pregnancy,” says Alise Carlson, MD, a neurologist and MS specialist at the Cleveland Clinic in Ohio. That’s because MS drugs may affect fetal development, and there is limited data on health outcomes because most of these drugs haven’t been studied during pregnancy.

For all MS drugs taken by mouth, Dr. Carlson says, it’s generally recommended to stop taking them before you become pregnant and for the duration of pregnancy. That’s because these drugs consist of small molecules that can easily pass through the placenta into a developing fetus.

But for certain MS medications taken by injection or infusion — known as monoclonal antibodies, or biologics — it may be possible to continue your normal course of treatment until you learn that you’re pregnant, if your doctor determines that it’s important for you to do so to avoid a relapse.

“We know that the transfer of these medications across the placenta doesn’t typically start until around the second trimester,” says Carlson. By this time, any medication in your body from an infusion before pregnancy has typically been “washed out,” even as the drug’s protection against MS relapses remains.

Navigating recommendations for different MS drugs can be difficult due to the patchwork of data that’s available, says Edith L. Graham, MD, a neurologist and MS specialist at Northwestern Medicine in Chicago. “In general, there has been exclusion of patients who are pregnant or breastfeeding from clinical trials,” she explains. “Historically, no one wanted the liability of studying outcomes” in these areas.

But certain recommendations have emerged largely because of data from pregnancy registries that include MS patients, says Dr. Graham. For example, people who take ocrelizumab (Ocrevus) can safely conceive about six weeks after their last infusion of the drug, she says. And it’s widely assumed that older injectable MS drugs like interferons and glatiramer (Copaxone) carry few risks related to pregnancy, although these drugs aren’t as effective as newer drugs at preventing relapses.

When it comes to MS drugs that work by targeting immune cells known as B cells — namely ocrelizumab and ofatumumab (Kesimpta) — the main risk of taking the medication during pregnancy is that a baby will be born with a low level of B cells. “But they quickly recover, and there has been no severe outcome because of that” in pregnancy registries, says Graham.

It’s important to talk with your doctor as early as possible about any plan or desire to become pregnant in the future, since this may affect what MS drug you’re prescribed in the first place.

Sometimes, women with significant disability due to MS may need or desire a C-section because the muscles may be too weak for vaginal delivery. “If they have motor weakness or sensory loss, that can contribute to difficulty with labor and delivery,” says Carlson. Women who are unable to walk because of MS may also be at greater risk for blood clots during pregnancy and may require close monitoring. Physical therapy can reduce this blood clot risk, Carlson says.

There is no documented connection between using pain control during delivery — such as an epidural block — and any MS-related risks, such as an increased relapse risk, says Graham.

Even though women with MS typically don’t continue to take their usual MS medications throughout pregnancy, many of them remain relapse-free.

“Overall, we know that MS disease activity decreases during pregnancy, because the immune system has shifted to a more tolerant state due to the presence of the fetus,” says Carlson. But that can end abruptly after giving birth. “Following delivery, there can be a sudden shift to a pro-inflammatory state that puts women at risk for relapse,” Carlson says.

Relapses can be safely confirmed using magnetic resonance imaging (MRI) without any injected contrast medium, says Graham. If a relapse is disabling and requires treatment, corticosteroids can be used. “Overall, we think that steroids are safe,” Graham says, but should still be limited to when treatment is absolutely necessary.

Because of a slightly increased risk of low birth weight and birth defects like a cleft palate, “We try to avoid using steroids during the first trimester whenever possible,” says Graham. If further action is needed to control a relapse, doctors may consider options like intravenous immunoglobulin (IVIG) or plasma exchange, but these treatments carry an increased risk of blood clots.

A mild relapse may not need any treatment at all, Carlson says. It’s up to you and your doctor to discuss the potential benefits and risks of treatment, and decide on a course of action.

In the past, many women with MS were given corticosteroids immediately after giving birth to reduce their relapse risk, but this practice is no longer routine and may be considered based on each person’s individual risk, says Graham. What’s more important, she says, is starting back on your MS medication. “I usually communicate with the obstetrician somewhere in the second or third trimester about what the plan is going to be to restart their disease-modifying therapy,” Graham says.

It’s important to discuss your plans regarding breastfeeding with your doctor ahead of time, since this may affect how soon you go back on your MS medication. If you decide not to breastfeed, your doctor will likely recommend resuming medications shortly after giving birth, according to Carlson.

If you do breastfeed and didn’t have highly active MS before you became pregnant, you may decide to hold off on taking medications. “Sometimes we’re comfortable monitoring patients during their breastfeeding journey, then resuming therapy once they’ve concluded breastfeeding,” says Carlson.

It’s generally considered safe to receive monoclonal antibodies for MS while breastfeeding, since these medications consist of large molecules that cannot easily pass into breast milk. Even if some of the medication is present in the milk, “What does transfer to the baby is broken down in the stomach” just like any protein and should have no effect on the baby, Carlson says.

Still, Graham typically waits two to three weeks following delivery to resume treatment with monoclonal antibodies, since the early form of breast milk — known as colostrum — may contain higher levels of medication if treatment begins right away.

Graham notes that breastfeeding itself may be somewhat effective as a way to prevent MS relapses after giving birth. “There is some evidence that exclusive breastfeeding does sustain a hormonal state that is similar to pregnancy and can be protective against MS relapse,” she says.

• Talk with your doctor as soon as possible about your pregnancy plans, since this can affect MS treatment decisions.
• Typically, you’ll stop taking MS medications during pregnancy, and any severe relapses can be treated using steroids.
• You’ll start back on your medications after giving birth, with the timing based in part on your breastfeeding plans.