Miller-Fisher syndrome (MFS) is the rare form of Guillain-Barre syndrome (GBS). The patient with signs of severe hyperemesis of gravidarum demonstarates development of Miller-Fisher syndrome in the second trimester of pregnancy. The morbidity is about 5-10%. It is considerable, that one third of pregnant patients need respiratory support in the period of disease. The article describes pathogenic treatment of Miller-Fisher syndrome in the aspect of potential risk for fetum and pregnant women.