Women have a higher rate of multiple sclerosis, an autoimmune disorder that affects the central nervous system, which consists of the spinal cord and the brain. Patients with multiple sclerosis develop symptoms as a result of demyelination, which is damage to the myelin, the covering of the neuron's axon.
The National Institute of Neurological Disorders and Stroke noted that women have the disorder twice as often as men; these rates do changes by age of onset. For example, men tend to develop the disorder later than women—in their 30s and 40s. When the gender ratio for multiple sclerosis is taken before the age of 20, the rate of women with multiple sclerosis is much higher: 3.2:1, according to Rhonda Voskuhl and Barbara S. Giesser, authors of the chapter “Gender and Reproductive Issues in Multiple Sclerosis” in the book Primer on Multiple Sclerosis.
One area of research in multiple sclerosis is changes in the disease during and after a pregnancy. Multiple sclerosis is not thought to impair infertility or cause higher rates of stillbirth, miscarriage, premature delivery or eclampsia. The National Multiple Sclerosis Society pointed out that multiple sclerosis patients who become pregnant may have a reduction in disease exacerbation; this reduction is more common during the second and third trimester. One issue that women with multiple sclerosis have to consider during a pregnancy is the possible effects that their disease-modifying medication may have on their unborn child. Voskuhl and Geisser noted that three disease-modifying medications for multiple sclerosis—mitoxantrone, cyclophosphaminde and azathioprine—have an FDA pregnancy risk of category D, which means there is “evidence of fetal harm in humans; use may be justified in some circumstances.”
Female multiple sclerosis patients who are considering becoming pregnant should talk to their doctors about their medications. While disease exacerbation is reduced during pregnancy, susceptibility for relapses may increase after giving birth--in particular, three to six months afterwards.