Hyperemesis gravidarum

HYPEREMESIS

• Aetiology not fully understood but related to HCG and TSH levels +/- psychological factors. 

There is, however, no direct relationship between the severity of the disorder and HCG or TSH levels

• An association exists with hyperthyroidism, pyridoxine deficiency, and psychological factors.

• Associated with metabolic alkalosis - hypochloraemic alkalosis with hypokalaemia and potassium loss in urine.

• Urine is acidic despite systemic alkalosis - when alkalosis is associated with volume depletion, bicarbonate is not excreted.

• Excretion of bicarbonate only occurs with restoration of extracellular fluid volume

• Wernicke's encephalopathy may occur - due to thiamine deficiency - consists of diplopia, ataxia, confusion and abnormal ocular movements.