It long has been known that women are at an increased risk for MS relative to men, but a recent study now raises the prospect that a woman’s childbearing status may affect her risk for earlier onset of progressive multiple sclerosis. [Zeydan 2020] A group of researchers from Mayo Clinic – who stress the need for this issue to be examined in a larger study – recently mapped disease course in 134 women and 68 men with progressive forms of MS. Those patients included both people with primary-progressive MS and those who transitioned from relapsing-remitting multiple sclerosis (RRMS) to secondary-progressive MS.

Among the women in the group, the 32 patients who had not given birth to a child had onset of progressive multiple sclerosis at an average age of 41.4 years, almost six years earlier than the average age for the 95 women who had delivered one or more children. That difference was statistically significant. Further, women who had delivered four or more children had an average age of progressive MS onset that was six years later than those who had delivered one to three children (52.6 years vs. 46.4 years, with the difference again being statistically significant).

Looking at the subgroup of patients who transitioned from RRMS to secondary-progressive MS, women who had not delivered a child also had a younger average age of RRMS diagnosis compared to those who did have children (27.5 years vs. 33.0 years, a statistically significant difference). Similarly, having given birth to four or more children was associated with a later average age of RRMS diagnosis than having delivered one to three children (35.8 years vs. 32.4 years, with the difference again being statistically significant).

While the findings are intriguing, the authors note that several questions require further investigation, including “whether MS-associated factors lead to nulliparity [not having delivered a child] either by choice or due to biological reasons.”