Hyperemesis Gravidarum

Introduction

• Description: Hyperemesis gravidarum is exaggerated nausea and vomiting during early pregnancy, which is sufficient to produce dehydration, metabolic disturbances, and weight loss. Alkalosis (from HCl loss) and hypokalemia are common.

• Prevalence: 70%–85% of women experience nausea; 50% have emesis in the first trimester; hyperemesis occurs in 0.5%–2% of pregnancies.

• Predominant Age: Reproductive age.

• Genetics: No genetic pattern.

Etiology and Pathogenesis

• Causes: Unknown. Most closely associated with hCG levels.

• Risk Factors: Multiple gestation, hydatidiform mole, ambivalence about pregnancy (debated), migraine headaches, female fetus (odds of female fetus 1.27), motion sickness, family history of hyperemesis. Alcohol and cigarette smoking appear to be protective to a small degree.

Signs and Symptoms

• Nausea and vomiting leading to weight loss, dehydration, ketone formation, and electrolyte disturbances (some define it as weight loss exceeding 5% of pre-pregnancy body weight)

• Aversions to tastes and smells

• Symptoms generally begin between the 4th and 8th week, lasting until 16 weeks or longer

Diagnostic Approach