Key TakeawaysPregnancy appears to reduce the onset of the first symptoms of multiple sclerosis for three years.The protective effect appears strongest in pregnancies that go through the second and third trimesters, when hormones calm an overactive immune system.Pregnancy hormones may change the expression of genes connected with the immune system, protecting not only the fetus but also reducing relapses of MS.Onset of MS was not further delayed in women with multiple pregnancies.

Key Takeaways

Pregnancy appears to reduce the onset of the first symptoms of multiple sclerosis for three years.The protective effect appears strongest in pregnancies that go through the second and third trimesters, when hormones calm an overactive immune system.Pregnancy hormones may change the expression of genes connected with the immune system, protecting not only the fetus but also reducing relapses of MS.Onset of MS was not further delayed in women with multiple pregnancies.

Pregnancy may delay the onset of the first symptoms of multiple sclerosis (MS) for more than three years, according to new research from Monash University in Australia.

MS affects three times more women than men, and the disease often is diagnosed during a woman’s childbearing years.Women with MS may struggle with the decision to start a family because they are unsure how their disease would affect their pregnancy. Now, a study of more than 2,500 women shows that pregnancy likely has a positive effect on MS.

The findings, published inJAMAon September 14, show the positive effect occurs with just one pregnancy and delivery. However, having multiple pregnancies and giving birth multiple times did not further delay the onset of symptoms.

The study looked at the reproductive histories of 2,557 women from the age of 16 to the point in time they experienced CIS. The researchers were able to analyze more than 10 years of follow-up data available in most cases. The results show the median delay in CIS diagnosis; 3.3 years if pregnant, 3.4 years with a live birth. Jokubaitis says there is no estimation of the maximum amount of time that CIS could be delayed.

“Everyone in our study did eventually develop CIS; pregnancy and childbirth cannot delay the onset of disease indefinitely,” Jokubaitis says. “Still, three extra years of living free of a first demyelinating event is a very long time.”

What MS Does To Your Body

MS is a chronic disease that affects the central nervous system—that is, the brain and the spinal cord. Nerves to the rest of the body branch out from the central nervous system to send and receive messages. If you burn your finger or cut your foot, nerves relay that news to your brain, and your brain quickly sends the signal to pull your hand away from the heat or lift your foot to see what you stepped on. But nerves also keep your heart beating and your lungs pumping. They send pain messages when you have a problem with an organ, such as a kidney stone, or a bladder infection.

“MS is an autoimmune condition where the immune system is overactive,” Jokubaitis says. The immune system cells attack the myelin protein, damaging nerves.

Living With Multiple Sclerosis

Pregnancy’s Effect On the Immune System

Pregnancy is well known for the way it changes a woman’s body on the outside: larger breasts, expanding belly, glowing skin. But many changes happen on the inside, too, not the least of which occur in the immune system.

The immune system goes through a number of stages to ensure a successful pregnancy, explains Jokubaitis. “Initially, the immune system needs to be more inflammatory to ensure successful embryo implantation,” she says.

Once the fetus is growing and developing, the immune system dampens down to protect the fetus. “The changes that the immune system undergoes to ensure a successful pregnancy means that, overall, it is less inflammatory,” Jokubaitis says. “This dampening down to protect the fetus also helps to alleviate MS symptoms.”

But as the body prepares to give birth, the immune system once agains becomes inflammatory, Jokubaitis says. “It could be that these periods of increased inflammatory activity to ensure pregnancy success might exacerbate an already overactive immune system, and lead to a first MS diagnosis in some women,” she says. “In our study [of more than 2,500 women], we actually identified 71 women, or 3% of our participants, who were diagnosed with a CIS during their pregnancy.”

Next Steps

Research will continue for women with MS. “In my laboratory, we are now seeking to understand the exact biological mechanisms that underpin improved outcomes in women with MS while they are pregnant,” Jokubaitis says. “Unfortunately, it’s not as straightforward as a single hormone being responsible for this [effect], as previous clinical trials have shown.”

What This Means For You

“There is some evidence that disease stability prior to pregnancy generally equates to fewer relapses or new disease activity postpartum,” Costello says.

How can you stabilize your MS? Costello recommends the following to help reduce symptoms and/or new disease activity, all of which you should discuss with your neurologist:

How Multiple Sclerosis Is Treated

3 SourcesVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Nguyen A, Vodehnalova K, Kalincik T, et al.Association of pregnancy with the onset of clinically isolated syndrome.JAMA Neurol.doi:10.1001/jamaneurol.2020.3324National Multiple Sclerosis Society.Pregnancy and Reproductive Issues.National Multiple Sclerosis Society.Clinically Isolated Syndrome (CIS).

3 Sources

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Nguyen A, Vodehnalova K, Kalincik T, et al.Association of pregnancy with the onset of clinically isolated syndrome.JAMA Neurol.doi:10.1001/jamaneurol.2020.3324National Multiple Sclerosis Society.Pregnancy and Reproductive Issues.National Multiple Sclerosis Society.Clinically Isolated Syndrome (CIS).

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.

Nguyen A, Vodehnalova K, Kalincik T, et al.Association of pregnancy with the onset of clinically isolated syndrome.JAMA Neurol.doi:10.1001/jamaneurol.2020.3324National Multiple Sclerosis Society.Pregnancy and Reproductive Issues.National Multiple Sclerosis Society.Clinically Isolated Syndrome (CIS).

Nguyen A, Vodehnalova K, Kalincik T, et al.Association of pregnancy with the onset of clinically isolated syndrome.JAMA Neurol.doi:10.1001/jamaneurol.2020.3324

National Multiple Sclerosis Society.Pregnancy and Reproductive Issues.

National Multiple Sclerosis Society.Clinically Isolated Syndrome (CIS).

Meet Our Medical Expert Board

Share Feedback

Was this page helpful?Thanks for your feedback!What is your feedback?OtherHelpfulReport an ErrorSubmit

Was this page helpful?

Thanks for your feedback!

What is your feedback?OtherHelpfulReport an ErrorSubmit

What is your feedback?