Nausea and vomiting of pregnancy.

NVP is a spectrum of disorders ranging from the physiologically typical mild to moderate nausea and vomiting that is usually self-limited, to the pathologic, intractable symptoms of hyperemesis gravidarum that are associated with metabolic and electrolyte disturbances and weight loss. Up to 90% of pregnant women experience NVP. The pathogenesis remains poorly understood with multifactorial theories proposed combining both biologic and psychological factors. Diagnosing this syndrome is straightforward, but other organic sources should be excluded when symptoms are severe or prolonged. The overall prognosis is excellent for typical NVP, but whether hyperemesis gravidarum increases the risk to the fetus is controversial. Initial management should be conservative, including reassurance of the transient nature of the symptoms and the good prognosis, in addition to dietary modifications. Pharmacologic therapy is reserved for patients with persistent symptoms and is appropriate after discussion of the risks and benefits with informed consent. Alternative treatments, including psychotherapy and other nonpharmacologic modalities, are less proven but potentially safe and effective, thus providing additional therapeutic options. In refractory cases, nutritional supplementation becomes life-saving for both the mother and the fetus. Therapeutic abortion is a rare and last resort, to be used only when maternal life is threatened.