According to a new study, the progression of multiple sclerosis, a long-term inflammatory condition of the central nervous system gets slower in women who give birth.
Belgian and Dutch researchers studied 330 women with MS for 18 years to reach the conclusion.
It was noted that in women who had children, the severe disability took longer to develop.
MS affects the transfer of messages from the nervous system to the rest of the body.
All the women, who were observed, visited a specialist center.
Their first symptoms of the disease was noted when they were between the age 22 and 38.
Of these women nearly a quarter of the women (24percent) were childless, while 170 had given birth before their symptoms developed (52 percent).
Also, 61 had their children after their symptoms developed (18 percent).
And 19 had had children both before and afterwards (6percent).
The researchers used a measuring technique called the Kurtzke Expanded Disability Status Scale (EDSS) to assess the progression of the disease.
The (EDSS) runs from one to 10, where 10 is death from MS and six is when an individual needs a cane, a crutch or a brace to walk 100m.
After an average of 18 years living with MS, 55 percent of the women were categorized as EDSS six.
However, the researchers noted that both the likelihood and speed of progression were affected by childbirth.
Women who had given birth were 34 percent less likely to progress to EDSS six than childless women, compared to women who had not had children.
"It's possible that the hormones released in pregnancy are having a beneficial effect on the immune system," the BBC News quoted Dr Maria D'hooghe from the National MS Center in Melsbroek, Belgium, which co-ordinated the study, as saying.
She added: "Certainly, animal studies show that pregnancy can lead to less damage in their brains.
"The other possibility is that it is lifestyle changes caused by having a baby that are delaying the effects of MS perhaps through increased activity or changes in the way we deal with stress."
However, Dr Susan Kohlhaas, research communications officer for the MS Society, suggested the research has not led to any definite conclusions.
She said: "It is difficult to form any meaningful conclusions from this research given the small size of the study and its flaws, but further studies will hopefully clarify the effects of pregnancy in women with MS."