Outcome of myasthenia gravis mothers and their infants

The aim of this retrospective study was to assess neonatal outcomes of pregnant women with myasthenia gravis (MG).

Pregnant women with MG who were treated in our hospital over an 8-year period were enrolled. Data relating to the course of the mother's MG (including the anti-acetylcholine receptor antibody (anti-AchR) titer and drug dosage), delivery mode, delivery course, puerperium period, and neonatal outcomes were obtained from the medical records.

Twelve women with MG had 13 pregnancies in our hospital from January 1997 to December 2005. None of the mothers needed intensive care. Two patients delivered vaginally, and ten delivered by cesarean section. Fourteen infants were born at an average gestational age of 37.2 +/- 2.0 weeks; their average birth weight was 2838.6 +/- 724.2 g. Two neonates (14.2%) had a congenital anomaly. Transitory neonatal myasthenia gravis (NMG) was diagnosed in one infant (7.1%).

In our study, MG exacerbations occurred in 38.5% of the patients. Postpartum, all MG patients experienced deterioration except one patient who deteriorated in the first trimester with a concomitant upper airway tract infection. Only 1 of the 14 neonates developed transient NMG; the incidence of transient NMG was lower than that previously reported. There was no correlation between the occurrence of NMG and the maternal anti-AChR titer. The cesarean section rate was approximately 33%; this high rate of elective cesarean sections in these MG patients could have prevented the occurrence of some of the complications related to vaginal delivery.