Research article

Myasthenia gravis and pregnancy: clinical implications and neonatal outcome

José F Téllez-Zenteno¹ , Lizbeth Hernández-Ronquillo^{* 2} , Vicente Salinas^{* 3} , Bruno Estanol^{* 1} and Orlando da Silva^{* 2}

¹Department of Neurology, National Institute of Medical Sciences and Nutrition. "Salvador Zubirán", Mexico City, Mexico

²Department of Pediatrics, University of Western Ontario, London, Ontario, Canada

³Neonatology Unit. National Institute of Perinatology, Mexico City, Mexico

author email corresponding author email* Contributed equally

BMC Musculoskeletal Disorders 2004, 5:42doi:10.1186/1471-2474-5-42

Published:	16 November 2004

Abstract

Background

The myasthenia gravis is twice as common in women as in men and frequently affects young women in the second and third decades of life, overlapping with the childbearing years. Generally, during pregnancy in one third of patients the disease exacerbates, whereas in two thirds it remains clinically unchanged. Complete remission can occur in some patients.

Methods

To describe the clinical course, delivery and neonatal outcome of 18 pregnant women with the diagnosis of myasthenia gravis. Retrospective chart review of pregnant patients with myasthenia gravis, followed at the National Institute of Perinatology in Mexico City over an 8-year period. Data was abstracted from the medical records on the clinical course during pregnancy, delivery and neonatal outcome.

Results

From January 1, 1996 to December 31, 2003 18 patients with myasthenia gravis were identified and included in the study. The mean ± SD maternal age was 27.4 ± 4.0 years. During pregnancy 2 women (11%) had an improvement in the clinical symptoms of myasthenia gravis, 7 women (39%) had clinical worsening of the condition of 9 other patients (50%) remained clinically unchanged. Nine patients delivered vaginally, 8 delivered by cesarean section and 1 pregnancy ended in fetal loss. Seventeen infants were born at mean ± SD gestational age of 37.5 ± 3.0 weeks and a mean birth weight of 2710 ± 73 g. Only one infant presented with transient neonatal myasthenia gravis. No congenital anomalies were identified in any of the newborns.

Conclusions

The clinical course of myasthenia gravis during pregnancy is variable, with a significant proportion of patients experiencing worsening of the clinical symptoms. However, neonatal transient myasthenia was uncommon in our patient population.