Myasthenia gravis and pregnancy: anaesthetic management--a series of cases.

BACKGROUND AND OBJECTIVE

Myasthenia gravis is an autoimmune neuromuscular disease, usually affecting women in the second and third decades. The course is unpredictable during pregnancy and puerperium. Myasthenia gravis can cause major interference in labour and partum and exacerbations of the disease frequently occur. The aim of this series of cases is to analyse retrospectively the anaesthetic management of myasthenia gravis patients and complications during the peripartum period.

MATERIALS AND METHODS

Retrospective, single centre study from clinical files of female myasthenia gravis patients who delivered between 1985 and 2007 at Hospital de Santo António, Porto, Portugal.

RESULTS

Seventeen myasthenia gravis patients delivered between 1985 and 2007 in Hospital Santo António. Two women were not included in the study as they had a spontaneous abortion in the first trimester. Four patients presented exacerbations of the disease during pregnancy, no exacerbation occurred in eight patients and three patients presented their first symptoms of myasthenia gravis during pregnancy (without diagnosis at time of delivery). Concerning the eight patients without exacerbations of the disease during pregnancy, pregnancy was brought to term in 87.5% of the cases; five women were submitted to nonurgent caesarean section (62.5%); and epidural block was performed in six patients (75%). No complications related to anaesthesia occurred in the peripartum period. Concerning the four patients with exacerbations of the disease, pregnancy was brought to term in three cases (75%); three women were submitted to nonurgent caesarean section (75%); and epidural block was performed in three patients (75%). One patient underwent an uncomplicated thymectomy under general anaesthesia during pregnancy and, in the postpartum period, there was a myasthenic crisis in another patient. Concerning the three patients without a myasthenia gravis diagnosis at partum, one woman already being followed for presenting muscular weakness had a vaginal delivery under epidural block, without complications; another patient, presenting discrete supine dyspnoea, was submitted to elective caesarean section under spinal block and developed severe dyspnoea that required mechanical ventilation and ICU admission; and in the remaining case, a woman presenting mild blurred vision was submitted to general anaesthesia, which resulted in delayed emergence, muscular weakness and respiratory failure. Pregnancy went full term in all cases (100%). No newborn had a myasthenic crisis.

CONCLUSION

Myasthenia gravis can interfere slightly with pregnancy and partum, although exacerbations of the disease occur frequently. Strict surveillance and therapeutic optimisation are crucial. In women with controlled disease, caesarean section should be carried out only if there are obstetric reasons. Locoregional anaesthesia is preferred, mainly epidural block. A good multidisciplinary cooperation, specific precautions and surveillance can certainly contribute to an improved outcome in myasthenia gravis patients during the peripartum period.