Two women with hyperemesis gravidarum were first seen with a short his
tory of confusion diplopia, unsteadiness, and fits caused by Wernicke'
s encephalopathy. The neurologic presentation had been precipitated by
a carbohydrate load inadvertently administered without Vitamin supple
mentation. We stress the importance of prescribing thiamine supplement
s to all women with prolonged vomiting during pregnancy.