Pregnancy can delay the onset of multiple sclerosis (MS) by more than three years, a world-first study conducted by Monash University researchers has found.
The first major study investigating delayed MS onset due to pregnancy, the findings suggest that delayed and reduced rates of pregnancy globally likely contribute to the increased incidence of MS among women of childbearing age.
The international study used a global database of more than 70,000 MS patients, with the condition, which affects 2.5 million worldwide, four times more prevalent in women than men.
Researchers say the findings have implications on both a greater understanding of the causes of MS and the potential for use of hormone therapy to delay the onset of symptoms.
Led by Dr Vilija Jokubaitis, from the Monash University Department of Neuroscience, and published in this week’s Journal of American Medicine Association Neurology Journal (JAMA Neurology), the study looked at whether pregnancy can delay the onset of MS, which is frequently diagnosed in women of childbearing years.
Dr Jokubaitis studied more than 3,600 women attending four MS clinics in Australia and the Czech Republic, all of whom were enrolled in the MSBase.
The study found women who have been pregnant were diagnosed with their first MS symptoms, on average, 3.3 years later compared to women who had never been pregnant. A similar delay in MS onset was also found in women who had carried a baby to term – with onset delayed, on average, by 3.4 years.
In the paper, Dr Jokubaitis suggests pregnancy could reduce the abnormal over-activity of the immune system that causes MS, potentially long-term.
“At present, we don’t know exactly how pregnancy slows the development of MS, but we believe that it has to do with alterations made to a woman’s DNA,” she said.
“We are now seeking funding to explore this exciting possibility.”
The Australian not-for-profit MSBase Registry has been following patients with MS across 35 countries since 2001. It coordinates and collates data from 160 collaborating clinics and follows 71,000 patients, which is helping support 56 prospective investigator-initiated studies across the globe.
Head of Research at MS Australia, Dr Julia Morahan, welcomed the study’s findings.
“With the incidence of MS increasing, especially in women, it is great to see Australian researchers investigating factors that might contribute to the development of MS in women and further delineating the relationship between pregnancy and MS onset.”
Read the full study here