Gestational diabetes linked to MS

People whose biological mothers had diabetes during pregnancy may be more likely to develop multiple sclerosis (MS) later in life, according to a large new study from Norway.

The research also suggests that birth size may play a role. People who were born larger than average had a slightly higher chance of developing MS as adults, while those born smaller than average appeared to have a lower risk across their lifetime.

MS is a long-term condition that affects the brain and spinal cord, where the immune system mistakenly damages healthy nerve tissue. While researchers know about several factors that can increase the likelihood of MS, the exact causes are still not fully understood.

Previous studies have shown that a mother’s health during pregnancy can influence a child’s risk of developing certain conditions later in life, particularly metabolic conditions. However, there has been limited research into whether pregnancy related factors might also influence the risk of MS.

To explore this further, researchers analysed national registry data covering more than 1.3 million people born in Norway between 1967 and 1989. They then linked this information with health records from later decades to identify which individuals went on to develop MS in adulthood. This allowed the team to look for patterns between pregnancy or birth factors and MS risk later in life.

The results showed that people whose biological mothers had diabetes during pregnancy were more than twice as likely to develop MS as adults. This included both long-term forms of diabetes and gestational diabetes, which can develop during pregnancy and usually resolves after birth.

The study also found a link between birth weight and MS risk. People who were born in the highest range for birth weight, compared to what would be expected for their stage of pregnancy, had around a 13 per cent higher chance of developing MS in adulthood. In contrast, those born in the lowest range had about a 12 per cent lower risk.

The reasons behind these links are not yet clear. One possible explanation is that diabetes during pregnancy may lead to long lasting changes in how a baby’s immune system develops. Another theory is that higher blood sugar levels during pregnancy may affect birth weight and trigger processes such as long term inflammation or lower vitamin D levels, which have previously been linked to MS risk.

Other pregnancy and birth factors, including being born early, having a mother with high blood pressure during pregnancy, or complications involving the placenta, were not linked to MS risk in this study.

Overall, the findings add to growing evidence that very early life factors, including those before birth, may play a part in shaping MS risk later on. The researchers stress that more studies are needed to confirm these results and to better understand the biological mechanisms involved.