the patient demographics to really draw some major conclusions.”
Among the unknowns are the treatments the women in the study were getting for MS or if perhaps the women who decided to have children were feeling better and having fewer symptoms.
Though much remains to be learned about the role of pregnancy in MS, a possible reason why it may help slow the progression of the disease is that during pregnancy, the immune system is “downregulated,” in part to prevent the mother’s body from rejecting the fetus, O’Looney explained. Suppressing the immune system may also help to control MS, O’Looney noted.
Treatments for MS, such as interferon beta-1a and -1b, work by suppressing the immune system.
A second possibility for why childbirth might help delay the progression of MS is that during pregnancy, estrogen levels rise. Previous research has suggested estrogen may help protect from MS by stimulating the cells that make myelin. The MS Society is currently funding a clinical trial in which women with MS are given estriol, a form of estrogen, along with standard MS treatments.
“The sex hormones do seem to have some neuroprotective role, though we are not quite sure how,” O’Looney said.
Still, O’Looney stressed that women should not interpret the results as reason to have a baby to delay the progression of the disease, or blame themselves if they decided not to have children.
“We still don’t know a lot about the great variability of MS, why does one person become more progressive while another follows a more benign course,” O’Looney said. “What’s certain is that one should not conclude it’s based on whether or not you have a child. There are so many other factors, including possibly genetic factors, that determine that.”
SOURCES: Marie D’hooghe, department of neurology, Nationaal MS Centrum in Melsbroek, Belgium; Patricia O’Looney, Ph.D., director, biomedical research, National Multiple Sclerosis Society; Nov. 24, 2009, Journal of Neurology, Neurosurgery & Psychiatry, online