Definition: Mild to moderate nausea and vomiting are seen commonly until approximately 16 weeks in most pregnant ladies. Although nausea and vomiting tend to be worse in the morning, thus erroneously termed morning sickness, they frequently continue throughout the day. In some cases, however, it is severe and unresponsive to simple dietary modification and antiemetics. Hyperemesis gravidarum is defined as vomiting sufficiently severe to produce weight loss, dehydration, alkalosis from loss of hydrochloric acid and hypokalemia. Rarely, acidosis from partial starvation and transient hepatic dysfunction develop. Modified PUQE scoring index (Pregnancy-Unique Quantification of Emesis and Nausea) can be used to quantify the severity of nausea and vomiting. Epidemiology: There appears to be an ethnic or familial predilection. The hospitalization rate for hyperemesis is around 0.5 to 0.8%. Hospitalization is less common in obese women. In women hospitalized in a previou...