Hyperemesis

Hyperemesis refers to severe, persistent vomiting that leads to dehydration, electrolyte abnormalities, and weight loss, and is not attributable to other common causes of nausea. When this condition occurs during pregnancy, it is commonly called hyperemesis gravidarum.

The exact cause of hyperemesis is not fully understood. In pregnancy, high levels of pregnancy hormones such as human chorionic gonadotropin and estrogen, as well as genetic and nutritional factors, are thought to contribute. Risk factors include a prior history of hyperemesis, multiple gestation or molar pregnancy, obesity, diabetes, migraines, and a history of nausea in previous pregnancies.

Typical features include prolonged vomiting that makes it difficult to keep fluids down, weight loss, dehydration, and reduced oral intake. Signs may include ketonuria and electrolyte disturbances, such as low potassium and metabolic alkalosis. Laboratory tests and imaging help exclude other illnesses, and pregnancy assessment confirms the diagnosis in the appropriate clinical setting.

Management focuses on stabilizing the patient, correcting dehydration and electrolytes, and ensuring adequate nutrition. Initial steps include IV fluids with electrolytes and thiamine, and antiemetic therapy. First-line medications commonly used are vitamin B6 with doxylamine; other options include metoclopramide, haloperidol, promethazine, and ondansetron. Severe cases may require enteral or parenteral nutrition and, rarely, corticosteroids.

The prognosis is generally good with proper treatment, though severe hyperemesis can cause maternal weight loss, electrolyte imbalance, and hospital admission. In pregnancy, it is associated with increased risk of dehydration, ketosis, and, in some studies, preterm birth or low birth weight. Recurrence in subsequent pregnancies is common.