Immunosuppressants May Help Lower Risk of Relapse in Pregnancy
Risk of NMOSD-associated relapse and disability is highest in postpartum period
Women with neuromyelitis optica spectrum disorder (NMOSD) who received immunosuppressive treatment during pregnancy or were at least 32 years old when they conceived may be at a lower risk of pregnancy-associated relapses, a systematic review study has found.
Data also showed the risk of relapse is highest in the first three months after giving birth (postpartum period), and that disease-associated disability is increased during pregnancy and the postpartum period.
NMOSD is an autoimmune condition that primarily affects the optic nerve, the spinal cord, and, in rare circumstances, the brainstem. The disorder occurs when the immune system mistakenly attacks nerve cells and their support cells. It’s most often characterized by periods of relapse, or disease flare-ups, with periods of recovery in between.
The condition primarily affects women, many of whom develop the disease during their childbearing years. The risk of relapse may be particularly high in the early postpartum period, with some women also experiencing disability worsening during pregnancy and postpartum, according to previous research.
To learn more about the factors associated with pregnancy-related NMOSD relapses, a team of researchers in China conducted a systematic review of 15 previously published studies that included data from 639 pregnancies among 443 women.
A pregnancy-related attack was defined as a disease relapse during pregnancy or within the year after giving birth.
Data showed that women using immunosuppressants during pregnancy had fewer relapses than those who did not. Among women who were at least 32 when they got pregnant, relapses were significantly less frequent than in women who were younger by the time they conceived.
Other factors, including disability at conception, co-existing autoimmune conditions, relapses in the year before pregnancy, age at disease onset, and time between disease onset and conception, were not linked to relapses.
Having antibodies against aquaporin-4, the most common type of antibody implicated in NMOSD, was also not associated with relapses.
The team then examined relapse rates and disability scores, as measured by the Annualized Relapse Rate (ARR) and Expanded Disability Status Scale (EDSS), respectively, during each phase of pregnancy compared with the year before pregnancy.
Highest relapse rates were found in the first three months after childbirth
Results showed that the highest relapse rates were observed in the first three months postpartum, which were significantly higher than those observed prior to pregnancy.
The lowest rate of relapse occurred in the last trimester of pregnancy, which was not significantly different than before pregnancy.
EDSS scores were significantly higher during and after pregnancy than before pregnancy, reflecting a worsening disability during the pregnancy period.
According to researchers, findings related to ARR and EDSS were similar to those previously observed in patients with multiple sclerosis, another autoimmune condition with many similarities to NMOSD.
Across 619 analyzed pregnancies, 30 babies were delivered prematurely, and there were 140 abortions, which included 50 spontaneous (miscarriages) and 90 elective abortions.
The “rate of spontaneous abortions was not higher in patients with NMOSD than [in] the general population,” the researchers noted.
Seventeen women experienced pre-eclampsia, a serious pregnancy complication characterized by high blood pressure. Health complications were observed in 33 infants, and included low birth weight, or abnormal fluid buildup in the brain (hydrocephalus).
“In this systematic review and meta-analysis, we identified factors associated with pregnancy-related NMOSD attacks, investigated the integrated ARR and EDSS scores in each phase of pregnancy, and summarized pregnancy outcomes and complications,” the researchers wrote.
They emphasized that while their findings highlight the importance of immunosuppressants during pregnancy, certain medications may not be recommended but can be replaced with safer options.
“Choosing appropriate immunosuppressive treatment during pregnancy to avoid pregnancy-related NMOSD attacks is of utmost importance,” they wrote.
The small sample size and differences across the evaluated studies limited the analyses, the team noted, adding that “high-quality prospective studies are needed.”