[Myasthenia gravis and pregnancy. Report on 13 cases]

To evaluate our experience of myasthenia during pregnancy.

Retrospective study in a tertiary care university hospital including pregnant women affected by myasthenia gravis and who delivered in the obstetrical tertiary center. Medical and delivery reports were analyzed.

Between 1994 and 2002, 12 women, age 31 (25-36), delivered 14 children. One women delivered twice, and there was one twin pregnancy. Clinical symptoms of myasthenia worsened in five. One was admitted twice to the intensive care unit during her pregnancy. Two were admitted to intensive care unit during the first month of post-partum. Gestational age at birth was 39.3 weeks (38-40.6), all birth weights were normal: 3329 g (2660-4520). Six women delivered vaginally, two by instrumental extraction and five by cesarean section. Apgar score was normal for all infants: 9/10. The level of anti-acetylcholine receptor antibodies (anti AchR) was high: 36.4 nM/L (0-46.8) (normal below 0.6 nM/L), but was not related to neonatal outcome. Three children presented neonatal myasthenia.

We recommend obstetrical monitoring in tertiary centers for pregnant women with myasthenia gravis because of the risk of neonatal myasthenia. Measurement of anti-acetylcholine receptor antibodies may be useful. Pediatric and maternal observation is necessary in the first days of post partum.