Neuromyelitis optica spectrum disorder, a disease often confused for multiple sclerosis, may increase a woman’s risk for miscarriage and preeclampsia during pregnancy, according to a study published in the November 18, 2015, online issue of Neurology.
The disorder causes inflammation in the central nervous system, affecting mainly the spinal cord and the nerves to the eyes, although the brain may be affected also.
“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,” said study senior author Maria Isabel Leite, MD, DPhil, of the University of Oxford in the United Kingdom. “So unfortunately, some of these women may not even know they are going to have the disease at the time of miscarriage.”
For the study, 60 women with a history of at least one pregnancy and a diagnosis of neuromyelitis optica spectrum disorder (NMOSD) were interviewed and their medical records were reviewed. Of those, 40 were analyzed for miscarriages and 57 for preeclampsia (high blood pressure and protein in the urine during pregnancy, which can threaten the life of the mother and baby).
Of the 40 women with a diagnosis of NMOSD, there were 85 pregnancies. Eleven pregnancies in six women (which represents 13 percent of all pregnancies) ended in miscarriage; this percentage is similar to the rate that occurs in the general population. 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. 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 rate of preeclampsia was also significantly higher, at 11.5 percent, than the 3.1 percent reported in the general population. The odds of preeclampsia were greater in women who also had multiple other autoimmune disorders or miscarriage in the most recent previous pregnancy, but disease onset was not a risk factor.
Leite said the main problems with this study are the small sample size, the fact that patients were studied retrospectively, and the lack of pathological data from placenta samples. “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,” said Leite.
About this neurology research
Funding: The study was supported by the UK National Specialised Commissioning Team.
Source: Rachel Seroka – AAN Image Credit: The image is in the public domain Original Research:Abstract for “Pregnancy outcomes in aquaporin-4–positive neuromyelitis optica spectrum disorder” by Matthew M. Nour, Ichiro Nakashima, Ester Coutinho, Mark Woodhall, Filipa Sousa, Jon Revis, Yoshiki Takai, Jithin George, Joanna Kitley, Maria Ernestina Santos, Joseph M. Nour, Fan Cheng, Hiroshi Kuroda, Tatsuro Misu, Ana Martins-da-Silva, Gabriele C. DeLuca, Angela Vincent, Jacqueline Palace, Patrick Waters, Kazuo Fujihara, and Maria Isabel Leite in Neurology. Published online November 18 2015 doi:10.1212/WNL.0000000000002208
Pregnancy outcomes in aquaporin-4–positive neuromyelitis optica spectrum disorder
Objective: To investigate the association between neuromyelitis optica spectrum disorder (NMOSD) and pregnancy outcome.
Methods: An international cohort of women with aquaporin-4 antibody–positive NMOSD and ≥1 pregnancy was studied retrospectively. Multivariate logistic regression was used to investigate whether pregnancy after NMOSD onset was associated with an increased risk of miscarriage (cohort of 40 women) or preeclampsia (cohort of 57 women).
Results: Miscarriage rate was higher in pregnancies after NMOSD onset (42.9% [95% confidence interval 17.7%–71.1%] vs 7.04% [2.33%–15.7%]). Pregnancies conceived after, or up to 3 years before, NMOSD onset had an increased odds ratio of miscarriage (7.28 [1.03–51.6] and 11.6 [1.05–128], respectively), independent of maternal age or history of miscarriage. Pregnancies after, or up to 1 year before, NMOSD onset ending in miscarriage were associated with increased disease activity from 9 months before conception to the end of pregnancy, compared to viable pregnancies (mean annualized relapse rate 0.707 vs 0.100). The preeclampsia rate (11.5% [6.27%–18.9%]) was significantly higher than reported in population studies. The odds of preeclampsia were greater in women with multiple other autoimmune disorders or miscarriage in the most recent previous pregnancy, but NMOSD onset was not a risk factor.
Conclusions: Pregnancy after NMOSD onset is an independent risk factor for miscarriage, and pregnancies conceived at times of high disease activity may be at increased risk of miscarriage. Women who develop NMOSD and have multiple other autoimmune disorders have greater odds of preeclampsia, independent of NMOSD onset timing.
“Pregnancy outcomes in aquaporin-4–positive neuromyelitis optica spectrum disorder” by Matthew M. Nour, Ichiro Nakashima, Ester Coutinho, Mark Woodhall, Filipa Sousa, Jon Revis, Yoshiki Takai, Jithin George, Joanna Kitley, Maria Ernestina Santos, Joseph M. Nour, Fan Cheng, Hiroshi Kuroda, Tatsuro Misu, Ana Martins-da-Silva, Gabriele C. DeLuca, Angela Vincent, Jacqueline Palace, Patrick Waters, Kazuo Fujihara, and Maria Isabel Leite in Neurology. Published online November 18 2015 doi:10.1212/WNL.0000000000002208