“We’re learning that pregnancy is a good thing for women with multiple sclerosis,” says Anthony T. Reder, MD, a professor of neurology at the University of Chicago Medicine and the director of its neurology and inflammatory disease infusion center. Up until the 1960s, women with multiple sclerosis were discouraged from becoming pregnant because of the concern that it could make the condition worse. But scientists have since observed that pregnancy reduces the likelihood of an MS relapse, particularly in the second and third trimesters.
Why Pregnancy Reduces MS Relapses
There is some debate as to why pregnant women tend to have fewer relapses. Dr. Reder says the benefits seem to come from the pregnancy hormone estriol; as estriol levels rise during pregnancy, the likelihood of an MS attack, or relapse, drops by about half, he says. Estriol modifies the immune system and helps prevent rejection of the fetus. Catherine Y. Spong, MD, the chief of the division of maternal-fetal medicine at UT Southwestern Medical Center and the vice chair of the department of obstetrics and gynecology at UT Southwestern Medical Center, in Dallas, says, “The benefits may also be due to pregnancy-related alterations in the body’s immune system [besides the rise in estriol].”
Does Your MS Raise Your Offspring’s Risk of MS?
The cause of MS is unknown, but it is believed to have a genetic component. That means that as you contemplate pregnancy, it’s good to consider your family history of MS. The risk of developing MS for someone without a first-degree relative (parent, sibling, or child) with MS is about 1 in 750 to 1,000, according to the National Multiple Sclerosis Society (NMSS). Children born to a mother (or father) with multiple sclerosis have a 3 to 5 percent risk of developing the disease, according to the Cleveland Clinic. The fact of having MS affects different adults’ family-planning decisions differently. For some it’s a reason not to have children or not to have more children. For others it does not factor into the decision of whether to have children. The right choice is the one that’s right for you.
What About Medication During Pregnancy?
If you want to get pregnant, first talk with your doctor about your current MS treatment and evaluate whether any medications should be changed or stopped, Dr. Spong says. Factors to consider include the type of medication, your personal medical history, and the significance of your MS attacks. “It really has to be individualized,” Spong says. If you have frequent symptom flares, you may be more inclined to stay on your MS disease-modifying medication, if it’s one that can be taken during pregnancy. While MS relapses do not seem to affect the fetus, they can last for as long as a month, and symptoms can range from fatigue or muscle weakness to trouble thinking and difficulty with speech or vision. A study published in Clinical Neurology and Neurosurgery examined the impact of disease-modifying drugs in a small group of pregnant women with multiple sclerosis: 89 took no MS medications and 61 took immunomodulators for at least eight weeks. The rate of complications between the two groups was similar, the researchers noted. But babies born to mothers who received treatment tended to have lower birth weight and height, while the rate of relapse was significantly higher in the group of mothers who abstained from treatment. New, larger studies show no decrease in birth weight, says Reder. According to Maria K. Houtchens, MD, an associate professor at Harvard Medical School and the director of the women’s health program at Partners Multiple Sclerosis Center at Brigham and Women’s Hospital in Boston, there are many new drugs on the market since 2013, when the study above was published. “This is a fast-moving field, and we want to refrain from making specific recommendations,” she says. Instead, Dr. Houtchens recommends keeping in mind the following:
There are many effective medications to treat MS.There are thousands of patients who have been exposed to injectable medications in early pregnancy, and there are no adverse outcomes reported as a result of this exposure.Newer medications are much trickier, and patients need to address each individual concern with their treating neurologist.The best source of information for both patients and other physicians is an MS expert who specializes in women’s health in MS and pregnancy.
A review of pregnancy management strategies — of which Houtchens was a coauthor — published in July 2019 in Multiple Sclerosis and Related Disorders offers drug-by-drug information on MS drug safety during pregnancy and breastfeeding and indicates that certain drugs, including Gilenya (fingolimod), Aubagio (teriflunomide), Mavenclad (cladribine), and Ocrevus (ocrelizumab) should be stopped before a woman becomes pregnant. The packaging materials for the drug Mayzent (siponimod) also state that it should not be taken during pregnancy. If you’re advised to stop taking your MS medications before you conceive, try to get pregnant as quickly as possible, so that the pregnancy hormones can take over as disease modifiers, Reder says. The longer the lag between stopping the medications and conceiving, the greater the risk the disease will progress. And be sure to take prenatal vitamins, including vitamin D and folic acid, adds Houtchens.
MS Relapses During and After Pregnancy
If you have a relapse during pregnancy, you may want to first try to manage it without medication. Corticosteroid medications such as prednisone and methylprednisolone, which are often used to treat relapses, may be used during pregnancy, according to the NMSS. But there is conflicting data on whether steroid medications may increase the risk of birth defects and miscarriage, so they should be used only in “the treatment of acute relapses that substantially impact daily life,” according to the 2019 review in Multiple Sclerosis and Related Disorders. After giving birth, your risk for an MS attack rises. The NMSS puts the risk of a postpartum exacerbation at 20 to 40 percent, but these relapses do not appear to contribute to long-term disability.
MS Drugs and Breastfeeding
Reder advises women who had active MS before pregnancy to restart their MS disease-modifying therapy as soon as possible after delivery. Some MS drugs are not recommended while you’re breastfeeding, because it’s not known whether the drug gets into the breast milk. Your doctor may know ways to combine breastfeeding and MS therapy, Reder says. Having an ongoing dialogue with your MS medical team, including your ob-gyn, will help you reach the best decisions for your personal circumstances. Additional reporting by Susan Jara.
