The risk of developing multiple sclerosis is significantly lower for women who have multiple pregnancies, new research suggests.
The study, published in the journal Neurology, found women who were pregnant two or more times had a quarter of the risk of developing MS symptoms than women who were never pregnant. Researchers also found women who had five or more pregnancies had one-twentieth the risk of developing symptoms than women who were never pregnant.
There appeared to be no connection between MS risk and fatherhood, according to the study by the Murdoch Children's Research Institute in Melbourne, Australia.
To reach their conclusions, researchers tracked the health of more than 280 Australian men and women between the ages of 18 and 59 with symptoms similar to MS but who had not yet been diagnosed with the disease. They were compared to more than 540 men and women with no MS symptoms.
For women, the number of pregnancies and live births were recorded. For men, the number of children born was recorded.
"In our study, the risk [among women] went down with each pregnancy and the benefit was permanent," said study author Anne-Louise Ponsonby.
She added: "The rate of MS cases has been increasing in women over the last few decades, and our research suggests that this may be due to mothers having children later in life and having fewer children than they have in past years."