WEDNESDAY, Nov. 18, 2015 (HealthDay News) -- An uncommon central nervous system disorder may increase pregnant women's risk for miscarriage or a serious pregnancy-related condition known as pre-eclampsia, a new study reveals.
The rare autoimmune disorder, called neuromyelitis optica, is often mistaken for multiple sclerosis. It affects the nerves to the eyes and the spinal cord, and sometimes the brain, the researchers explained.
In the new study, Dr. Maria Isabel Leite from the University of Oxford in England, and colleagues looked at the medical records of 60 pregnant women with neuromyelitis optica who'd had at least one previous pregnancy.
Forty of the women were analyzed for miscarriage and 57 for pre-eclampsia, which is marked by high blood pressure and protein in the urine during pregnancy that can threaten the life of the mother and baby.
Of the 40 women analyzed for miscarriage, there were 85 pregnancies. Eleven pregnancies in six of the women (13 percent) ended in miscarriage, a rate similar to that in the general population, according to the study published online Nov. 18 in the journal Neurology.
"But six of the 14 pregnancies (43 percent) that occurred after the disease started ended in miscarriage. Pregnancies conceived up to three years before disease onset were nearly 12 times as likely to end in miscarriage, regardless of the mother's age or past history of miscarriage," according to a journal news release.
"Women whose pregnancies ended in miscarriage after or up to one year before the disease began also had more disease activity from nine months prior to conception to the end of pregnancy, compared to viable pregnancies," the researchers reported.
The rate of pre-eclampsia among women with neuromyelitis optica was 11.5 percent, compared with about 3 percent in the general population. The risk of pre-eclampsia was even higher among women with neuromyelitis optica who had other autoimmune disorders or had suffered a miscarriage in their most recent pregnancy, the investigators found.
"Women with neuromyelitis optica have a high risk of miscarriage, particularly in pregnancies occurring within the three years prior to, or after, when the disease starts. So unfortunately, some of these women may not even know they are going to have the disease at the time of miscarriage," Leite said in the news release.
"Larger studies need to be done to confirm our findings. However, our study suggests that preventing disease activity prior to and during pregnancy appears to be essential to improving pregnancy outcomes in women with neuromyelitis optica," she concluded.
The U.S. National Institute of Neurological Disorders and Stroke has more about neuromyelitis optica.