THE CLINICAL PROBLEM
About 50% of women have nausea and vomiting in early pregnancy, and an additional 25% have nausea alone.1,2 The popular term “morning sickness” is a misnomer, since this condition often persists throughout the day.2 In about 35% of women who have this condition, nausea and vomiting are clinically significant, resulting in lost work time and negatively affecting family relationships.3,4 In a small minority of patients, the symptoms lead to dehydration and weight loss requiring hospitalization.5 The reported incidence of hyperemesis gravidarum is 0.3 to 1.0%; this condition is characterized by persistent vomiting, weight loss of more than 5%, ketonuria, electrolyte abnormalities (hypokalemia), and dehydration (high urine specific gravity).5,6