Hyperemesis gravidarum: A review of recent literature

Background: In the United States, hyperemesis gravidarum is the most common cause of hospitalization during the first half of pregnancy and is second only to preterm labor for hospitalizations in pregnancy overall. In approximately 0.3-3% of pregnancies, hyperemesis gravidarum is prevalent and this percentage varies on account of different diagnostic criteria and ethnic variation in study populations. Despite extensive research in this field, the mechanism of the disease is largely unknown. Although cases of mortality are rare, hyperemesis gravidarum has been associated with both maternal and fetal morbidity. The current mainstay of treatment relies heavily on supportive measures until improvement of symptoms as part of the natural course of hyperemesis gravidarum, which occurs with progression of gestational age. However, studies have reported that severe, refractory disease manifestations have led to serious adverse outcomes and to termination of pregnancies. Summary: Despite extensive research in the field, the pathogenesis of hyperemesis gravidarum remains unknown. Recent literature points to a genetic predisposition in addition to previously studied factors such as infectious, psychiatric, and hormonal contributions. Maternal morbidity is common and includes psychological effects, financial burden, clinical complications from nutritional deficiencies, gastrointestinal trauma, and in rare cases, neurological damage. The effect of hyperemesis gravidarum on neonatal health is still debated in literature with conflicting results regarding outcomes of birth weight and prematurity. Available therapy options remain largely unchanged in the past several decades and focus on parenteral antiemetic medications, electrolyte repletion, and nutritional support. Most studies of therapeutic options do not consist of randomized control studies and cross-study analysis is difficult due to considerable variation of diagnostic criteria. Key Messages: Hyperemesis gravidarum carries a significant burden on maternal health and US health care. Most published research on pathogenesis is observational and suggests multifactorial associations with hyperemesis gravidarum. Precise, strictly defined criteria for clinical diagnosis are likely to benefit meta-analyses of further research studies regarding pathogenesis as well as therapeutic options.