[Hyperemesis gravidarum: a rare but potentially severe complication of the first trimester of pregnancy].

Although nausea and vomiting are common symptoms in early pregnancy, hyperemesis gravidarum (HG) is a rare complication of the first trimester of pregnancy. This condition is defined as intractable vomiting occurring before 20 weeks of gestation, with fluid and electrolyte disturbance, significant weight loss, and ketonuria, leading to hospitalization in the absence of other cause than pregnancy. Some biological disturbances found in HG, such as hyperthyroidism and hepatic cytolysis, which are correlated with the importance of vomiting, are without severe clinical consequences, but may represent diagnostic pitfalls. The aetiology is unknown, but human chorionic gonadotropin hormones likely play the first role. Psychological disturbance is currently seen as the result of the burden and stress of HG rather than a causal factor. Maternal outcome may be severe in the absence of treatment, but pregnancy outcome seems good, as far as the condition has been adequately controlled. The management of HG includes IV rehydration, thiamine supplementation, antiemetic drugs (doxylamine, metoclopramide and chlorpromazine being the first-line choices), and in severe cases, nasogastric or parenteral nutrition. A psychological support is often necessary.