Annualized relapse rates were elevated compared with the prepregnancy period, especially during the initial 3 months after delivery, whereas EDSS scores worsened during pregnancy and the postpartum period.
Chao Quan, MD
Findings from a systematic review and meta-analysis of 15 studies suggest that treatment with an immunosuppressive agent during pregnancy and older age at conception were associated with protection against pregnancy-related neuromyelitis optica spectrum disorder (NMOSD) attacks. Most attacks occurred in the first 3 months of the postpartum period; however, investigators concluded that high-quality prospective studies are needed to validate the data.1
The analysis aimed to identify factors associated with pregnancy related NMOSD attacks, understand the annualized relapse rate (ARR) and Expanded Disability Status Scale (EDSS) score at each phase of pregnancy, and summarize pregnancy outcomes and complications in those with NMOSD. Conducted by Chao Quan, MD, of the Department of Neurology and Huashan Rare Disease Center, Huashan Hospital and Shanghai Medical College, Fudan University, the final cohort included data on 443 patients with NMOSD with 639 informative pregnancies, with the aquaporin-4 antibody (AQP4-Ab) positivity rate ranging from 48.3% to 100%.
A subgroup of 7 studies included data on patients receiving immunosuppressive treatment before and during pregnancy, regardless of the duration and kind. Here, the data showed that the rate of pregnancy related NMOSD attacks was significantly lower among those on immunosuppressives compared with those who were not (rate ratio [RR], 0.43; 95% CI, 0.32-0.57; P <.001). In the meta-regression analysis, a negative association was observed between the rate of immunosuppressive treatment during pregnancy and the rate of pregnancies with pregnancy-related NMOSD attacks (odds ratio [OR], 0.46; 95% CI, 0.29-0.72; P = .006).
In total, 5 studies with 210 informative pregnancies were included in the age at conception subgroup analysis, with older age considered at least 32 years. Findings demonstrated that younger age at conception was association with significantly lower pregnancy related NMOSD attacks (RR, 0.67; 95% CI, 0.47-0.95; P = .02). On meta-regression analysis, the rate of pregnancies with pregnancy related NMOSD attacks was not statistically significant based on age at conception (OR, 0.98; 95% CI, 0.89-1.08; P = .60).
ARR at each phase of pregnancy, annualized in 12 studies, was the highest at 1.86 (95% CI, 1.47-2.25) in months 0 to 3 of the postpartum period (PP1), while the lowest ARR, 0.36 (95% CI, 0.03-0.70), was in the third trimester. The difference in ARR was statistically significant between before pregnancy and PP1 (mean difference [MD], 1.28; 95% CI, 0.94-1.62; P <.001); however, the differences in ARR were not statistically significant between before pregnancy and the other phases of pregnancy (trimester 1: MD, –0.17 [95% CI, 0.35-0.02]; P = .08; trimester 2: MD, –0.12 [95% CI, –0.31 to 0.07]; P = .21; trimester 3: MD, –0.03 [95% CI, –0.41 to 0.01; P = .06) or postpartum (PP2: MD, 0.27 [95% CI, –0.01 to 0.54]; P = .06; PP3: MD, –0.03 [95% CI, –0.20 to 0.15]; P = .78).
In a subgroup analysis evaluating EDSS score at each phase, the scores increased significantly during pregnancy (MD, 0.44; 95% CI, 0.20-0.69; P <.001) and postpartum (MD, 0.88; 95% CI, 0.51-1.26; P <.001) compared with EDSS scores observed before pregnancy. Additionally, a separate subgroup analysis found no statistically significant difference in rate of pregnancies with pregnancy related NMOSD attacks in the group with coexisting autoimmune disease compared with those without (RR, 1.25; 95% CI, 0.99-1.57; P = .06).
Pregnancy outcomes and complications of the informative pregnancies in NMOSD were highlighted in 15 studies. Among 619 informative pregnancies, there were 396 term deliveries (64.0%), 30 premature deliveries (4.8%), 140 abortions (22.6%) and 17 patients who developed preeclampsia (2.7%). Of those who aborted, 50 (8.1%) were spontaneous and 90 (14.5%) were elective. Additionally, there were 33 births (5.3%) with neonatal complications, including various health issues.