Study Investigates Risk of Myasthenia Gravis Flare-Ups During Pregnancy
KEY TAKEAWAYS
- Pregnancy was not associated with an increased risk of serious myasthenia gravis flare-ups requiring hospitalization in a nationwide Swedish cohort study
- A small proportion of participants had MG-related hospitalizations in the first year after birth, and postpartum hospitalization risk was higher after adjustment.
- The study did not capture milder flare-ups that did not require hospitalization or medication escalation.
A nationwide Swedish cohort study published in Neurology found that pregnancy was not associated with increased risk of serious myasthenia gravis (MG) exacerbations requiring hospitalization or new symptoms. The postpartum period, however, was associated with increased risk in a small subset of participants. The findings from this study are relevant for neurologists of female patients of childbearing age with MG: a group in which approximately 70% report fear of exacerbation as a barrier to pregnancy.
Researchers analyzed records from 112 women with MG who had 176 pregnancies documented in the Swedish Medical Birth Register between 1987 and 2019. The study compared MG-related hospital admissions during pregnancy and in the year after birth with admissions in the year before birth. The analysis also assessed whether hospitalizations lasted longer during pregnancy or after delivery.
Key Findings
- Pregnancy was not associated with increased MG hospitalization risk compared with the pre-pregnancy year (hazard ratio [HR], 0.74; 95% CI, 0.39 to 1.41), and there was no increased risk of longer hospitalizations (HR, 0.83; 95% CI, 0.36 to 1.88).
- The postpartum period was associated with a significantly elevated risk of prolonged MG hospitalizations during the full first year (HR, 4.52; 95% CI, 1.26 to 16.14) and the first 3 months (HR, 5.02; 95% CI, 1.66 to 15.24).
- Only 10.8% of pregnancies (19/176) required MG hospitalization in the first postpartum year, suggesting that exacerbations were severe but occurred in a minority of individuals.
- Immunosuppressive medications were escalated in 6 pregnancies and reduced or discontinued in 13 during pregnancy, and medications were escalated in 10 pregnancies and reduced in none during the postpartum period.
- Postpartum exacerbations were not consistent across pregnancies in the same individual, highlighting the unpredictability of the peripartum MG course.
Source
O'Connor L, Gabrysch K, Wikström A-K, et al. Risk of myasthenia gravis exacerbation during pregnancy and postpartum. Neurol. 2026;106(12):e218082. doi:10.1212/WNL.0000000000218082