
The risk, however, increases with age
Women who had had her last child in the last five years were 71 percent less likely to RA than women without children. In contrast, the risk was 24 percent lower in women who had given birth more than 15 years ago.
“The most interesting result was the relationship between the risk of acquiring this disease and the time from birth, particularly how that relationship weakened over time, because it supports our hypothesis that fetal cells, we now know that last decades after birth, would be good for the mother, “said Guthrie.
The team found that 9 percent of the 120 participants who had had a child in the last five years, suffered from Rheumatoid Arthritis (RA). So did 14 percent of 345 women who had given birth to between five and 15 years earlier and 17 percent of 805 mothers who were for more than 15 years.
24 percent of the 406 women without children suffering RA. But since the study compared a group of women with RA with a healthy group, those percentages do not reflect women’s risk of RA according to their obstetric history.
Fetal cells and level of protection
The new findings do not prove that having children reduces a woman’s risk of getting AR. But it is possible, “said Guthrie, that fetal cells remain in the mother’s body will provide some level of protection.
These fetal cells are genetically distinct from those of the mother, because half of the genes of the children from the father. And if the cells carry genes that reduce the risk of AR, that could, in theory, change in a woman’s chance of developing the disease.