Summary: Severe hyperemesis gravidarum causes profound maternal morbidity. Termination of pregnancy is still offered before the use of medical therapy. This report describes management of a woman who had undergone two previous terminations for hyperemesis, and additionally presents the dosage profile of prednisolone used to successfully manage a consecutive series of 33 women with severe hyperemesis gravidarum. The treatment protocol is described. The group had a median weight loss in pregnancy of kg (range – kg), had been admitted on a median of (range 0 – 9) occasions and had spent (range 0 – 25) days on . fluids. Continuing vomiting prevented oral steroid therapy in 14 women and . hydrocortisone (50 mg .; two women required 100 mg .) was used initially for 24 – 48 h. Nineteen women commenced prednisolone 10 mg . and this achieved suppression of vomiting within 48 h in all but two women who required 15 mg . Two distinct subtypes of hyperemesis gravidarum were identified. Remitting hyperemesis spontaneously ceases between 14 and 22 weeks gestation and accounts for approximately 80% of cases. In contrast, full-term hyperemesis persists until minutes after delivery. These separate sub-types have not previously been described. Steroid treatment of hyperemesis should be considered in women who fulfil the criteria of severe disease.