Nausea and Vomiting of Pregnancy

Nausea and vomiting of pregnancy is a common condition with prevalence rates for nausea of 50–80% and for vomiting and retching of 50% (5). An estimated 50% of pregnant women have nausea and vomiting, 25% have nausea only, and 25% are unaffected (6, 7). Recurrence of nausea and vomiting of pregnancy with subsequent pregnancies ranges from 15.2% to 81% (8). One study has attempted to categorize nausea and vomiting of pregnancy into degrees of severity by assessing the duration of nausea and vomiting each day (from less than 1 hour in mild cases to more than 6 hours in severe cases) and the amount of vomiting and retching per day (up to two times for mild and moderate nausea and vomiting of pregnancy and more than five times in severe cases) (1). However, although these categories recognize nausea and vomiting of pregnancy as a continuum, they may not be clinically useful. The woman’s perception of the severity of her symptoms, her desire for treatment, and the potential effect of treatment on her fetus are more likely to influence clinical decision making. Early treatment of nausea and vomiting of pregnancy is recommended to prevent progression to hyperemesis gravidarum. From an epidemiologic perspective, hyperemesis gravidarum appears to represent the extreme end of the spectrum of nausea and vomiting of pregnancy (9). The incidence of hyperemesis gravidarum is approximately 0.3–3% of pregnancies (5). The reported incidence varies because of different diagnostic criteria and ethnic variation in study populations. There is no single accepted Nausea and Vomiting of Pregnancy