A case series of rare neurological and cardio-pulmonary manifestations of thiamine deficiency in pregnancy and lactation.

Thiamine (vitamin B1) is a sulfur-containing, water-soluble vitamin that plays an essential role in energy metabolism and the tricarboxylic acid cycle. There is an increased need for vitamin B1 (1-1.2 mg daily) during pregnancy and lactation. Hyperemesis during pregnancy can cause severe polyneuropathy (Wernicke's encephalopathy) as a result of thiamine deficiency. Thiamine deficiency has also been associated with beriberi. A number of atypical cases with reversible right heart failure and severe pulmonary hypertension have also been reported in non-pregnant individuals, but have never been reported in pregnancy. Here we present five such cases of thiamine deficiency with neurological and cardio-pulmonary manifestations.