By Margarita Nahapetyan
Pregnancy may decrease a woman's risk of developing the debilitating illness multiple sclerosis, Australian researchers have found. It has already been known that pregnancy can cause a remission in symptoms of this autoimmune disease, but the new findings suggest that having more children may prevent multiple sclerosis from ever developing.
To come up with this conclusion, researchers reviewed information of nearly 300 men and women, aged between 18 and 59 years, who had been diagnosed of central nervous demyelination. This is a condition that reflects early symptoms of multiple sclerosis, such as walking problems, fatigue, numbness and problems with balance, but is not an actual diagnosis of the disease. Scientists looked at both the number of live births and pregnancies in the women that lasted for at least 20 weeks. They also took into consideration the number of children men had and, finally compared all those statistics to 542 men and women who had never experienced symptoms of MS.
When the results were analyzed, researchers could find no link between the number of children that were born to men and their increased risk of developing MS symptoms. However, they found an association with the ladies: the risk of developing MS symptoms decreased with an increased number of pregnancies. In particular, women who had at least one child had about 50 per cent less the risk of developing early MS symptoms when compared to women without children. And the risk was dropping with each additional child. Women who had three kids had a 75 per cent lower risk of early MS symptoms compared to those with no children. And ladies who had 5 kids or more slashed their risk of developing the early symptoms by 94 per cent.
All the benefits remained even after the experts accounted for other factors, such as smoking, skin damage, genetics, level of education and sun exposure that are associated with the likelihood of developing the MS disease. It still remains unclear why pregnancy may decrease the risk of developing MS, but scientists speculate that it could be due to the increased levels of estrogen during pregnancy or the effect pregnancy has on inflammatory genes that are associated with MS.
Multiple sclerosis is a disease in which the nerves of the central nervous system - brain and spinal cord - gradually degenerate. Inflammation causes the myelin, which is essential for the proper functioning of the nervous system, to disappear. As a result, the electrical impulses that travel along the nerves become much slower. Also, the nerves themselves get damaged, and as more and more nerves are affected, people start experiencing a progressive interference with functions that are controlled by the nervous system such as walking, memory, vision, speech and writing.
The study was funded by the National Multiple Sclerosis Society and other organizations. It is published online in the journal Neurology.