Canadian scientists believe they may be some way to solving the mystery of why women suffering from multiple sclerosis (MS) go into remission while they are pregnant.
According to University of Calgary researchers the hormone prolactin, which is produced in abundance during pregnancy, is responsible for rebuilding the protective coating around nerve cells.
A woman's body produces prolactin in the greatest quantities during pregnancy in order to prepare the body for breast-feeding and the researchers believe this could be the key to treating the devastating neurodegenerative disease.
Multiple sclerosis is caused by the body's immune system turning on itself and attacking myelin, the protective fatty sheath that surrounds the nerve fibres in the brain and spinal cord.
This leads to a progressive loss of sensation and movement.
MS affects approximately 2.5 million people worldwide and Canadians have one of the highest rates of the disease in the world.
The Canadian team have found that prolactin can repair the damaged nerve cells responsible for the disease's devastating symptoms.
They hope the discovery will provide new ways to reverse some of the effects of the disease and improve the quality of life for those who live under its influence.
For their study the Canadian scientists compared pregnant and virgin female mice of the same age and found that pregnant mice had twice as many myelin-producing cells, called oligodendrocytes, and continued to generate new ones during pregnancy.