TOPLINE:

Among women with myasthenia gravis, pregnancy was not associated with an increased risk for exacerbations of myasthenia gravis. However, the postpartum period was linked to a significantly higher risk for prolonged hospital stays for exacerbations in a small subset of women during the first year after delivery.

METHODOLOGY:

• Researchers used data from a national register for myasthenia gravis linked to the Swedish Medical Birth Register and conducted a population-based cohort study to assess the risk for exacerbations of myasthenia gravis during pregnancy and up to 1 year postpartum.
• They included 112 women with myasthenia gravis (median age, 30 years) who had 176 singleton pregnancies documented in the Medical Birth Register following a diagnosis of myasthenia gravis between 1987 and 2019. The median disease duration at the time of pregnancy was 8 years.
• The primary outcome was exacerbation of myasthenia gravis, defined by the rate and duration of hospital admissions with myasthenia gravis recorded as the primary or any diagnosis.
• The secondary outcome was change in immunosuppressive medication use for myasthenia gravis during pregnancy and up to 1 year postpartum.

TAKEAWAY:

• During pregnancy, the rate of hospital admissions for myasthenia gravis as the primary diagnosis did not differ significantly between pregnancy and the year before pregnancy, and the risk for longer hospital admissions was not elevated.
• The postpartum period was associated with an increased risk for prolonged myasthenia gravis-related hospital stays in the first 3 months (hazard ratio [HR], 5.02; 95% CI, 1.66-15.24), with a similar elevated risk observed up to 1 year postpartum (HR, 4.52; 95% CI, 1.26-16.14).
• The risk for prolonged hospital stays for myasthenia gravis as the primary diagnosis was also higher outside of pregnancy than during the prepregnancy year (HR, 2.95; 95% CI, 0.84-10.43).
• Immunosuppressive medications were reduced without the need for switching to alternative agents in 13 pregnancies, but during the postpartum period, medications were initiated or escalated in 10 pregnancies.

IN PRACTICE:

"Exacerbations varied across pregnancies within the same individual, highlighting the unpredictability of MG [myasthenia gravis] in the peripartum period. Vigilant postpartum monitoring and individualized care remain essential," the authors wrote.

SOURCE:

This study was led by Laura O'Connor, Uppsala University in Uppsala, Sweden. It was published online on May 13, 2026, in Neurology.

LIMITATIONS:

Data on disease severity scores, particularly before 2001, were incomplete, which may have limited the application of standardised definitions of exacerbations. The study relied on hospital admissions as a proxy for exacerbations of myasthenia gravis, likely capturing more severe events. The findings applied only to pregnancies that reached at least 22 weeks of gestation, and data on breastfeeding were not available.

DISCLOSURES:

This study was supported by the Erling-Persson Foundation and ALF Funding from Region Uppsala. One of the authors declared receiving speaking honoraria and honoraria for advisory board participation from various pharmaceutical companies.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.