Case Report: Pharmacological decision-making in pregnant women with neuromyelitis optica spectrum disorder: two contrasting clinical scenarios.

Background: Neuromyelitis optica spectrum disorder (NMOSD) is a relapsing autoimmune disease of the central nervous system that predominantly affects women of reproductive age. Pregnancy requires careful pharmacological decision-making because maternal relapse can lead to severe neurological disability, while fetal exposure to immunosuppressive therapy remains an important safety concern. Case presentation: We report two contrasting clinical scenarios in pregnant women with NMOSD. Case 1 involved a 30-year-old primigravida with AQP4-IgG-negative NMOSD and weak isolated MOG-IgA positivity of uncertain clinical significance. At 11 weeks of gestation, she developed a disabling relapse with severe bilateral lower-limb weakness, sensory disturbance, inability to walk independently, and urinary dysfunction. High-dose intravenous methylprednisolone led to partial recovery. After multidisciplinary counseling, she chose pregnancy termination at 18+3 weeks because of residual disability, concerns about fetal drug exposure, possible need for further immunosuppression, and anticipated rehabilitation burden. Case 2 involved a 35-year-old primigravida with AQP4-IgG-positive NMOSD who had been clinically stable for approximately 1 year before conception while receiving prednisolone 10 mg/day and azathioprine 50 mg/day. This regimen was continued during pregnancy with neurological, obstetric, and clinical pharmacology monitoring. She remained relapse-free and delivered a healthy female infant at 38 weeks. The infant weighed 3,100 g, had Apgar scores of 10, 10, and 10 at 1, 5, and 10 min, and showed normal growth and development at 12 months. Conclusion: These cases are not directly comparable and cannot establish treatment efficacy or pregnancy outcome causality. They highlight the need for preconception counseling, individualized risk-benefit assessment, careful use of pregnancy-compatible maintenance therapy when clinically indicated, and multidisciplinary follow-up. Isolated weak MOG-IgA positivity requires cautious interpretation.