ACOG Updates Pregnancy Nausea/Vomiting Treatment Guidelines

Marcia Frellick

August 20, 2015

Guidelines published online August 19 by the American College of Obstetricians and Gynecologists (ACOG) and in the September issue of Obstetrics & Gynecology review the evidence on diagnosing and managing nausea and vomiting during pregnancy.

Among the new guidelines, replacing those from 2004, are updates on widely known treatments. The combination of doxylamine and vitamin B6, which was taken off the market in 1983, is back and has been proven safe and effective. ACOG says the combination should be considered first-line pharmacotherapy.

For ondansetron, the review includes a list of medications that patients taking the drug should avoid. Although some studies have shown an increased risk for birth defects with early ondansetron use, other studies have not, and the absolute risk to any fetus is low, according to the review. As with all medications, the risks and benefits should be weighed in each case.

Symptoms Underreported and Undertreated

An estimated 50% of pregnant women experience nausea and vomiting, 25% have nausea only, and 25% are unaffected, the authors report. Recurrence with subsequent pregnancies ranges from 15.2% to 81%.

However, nausea and vomiting may not receive the attention they need for several reasons. One is that "morning sickness" is common in early pregnancy, so pregnant women and their physicians may minimize the concern, and it may be undertreated. Also, women may not seek help because of concerns about the safety of medications.

However, the guideline authors note that treating nausea and vomiting early in pregnancy, before it progresses, can help control symptoms and prevent more serious complications, including hospitalization.

Considering the timing of the start of nausea or vomiting is important. Symptoms almost always present before 9 weeks of gestation. When nausea or vomiting begins for the first time after 9 weeks, other conditions should be considered.

Other recommendations based on good and consistent scientific (level A) evidence include:

  • The standard recommendation to take prenatal vitamins for 3 months before conception may reduce the incidence and severity of nausea and vomiting in pregnancy.

  • In patients with hyperemesis gravidarum who also have suppressed thyroid-stimulating hormone levels, treatment of hyperthyroidism should not begin without evidence (such as goiter, thyroid autoantibodies, or both) of thyroid disease.

Among recommendations based on limited or inconsistent scientific evidence (level B):

  • Treatment with ginger has shown benefit in reducing nausea and can be considered a nonpharmacologic option.

  • Treatment of severe nausea and vomiting of pregnancy or hyperemesis gravidarum with methylprednisolone may be effective in refractory cases; however, the risk profile of methylprednisolone suggests it should be used as a last resort.

The authors acknowledge that variations in treatment may be warranted based on the needs of the individual patient, resources, and limitations unique to the practice.

Whether, when, and how to treat nausea and vomiting of pregnancy should also depend on the woman's perception of the severity of her symptoms. Easing the symptoms can add to women's quality of life, lower healthcare costs, and shorten time away from work.

Obstet Gynecol. 2015;126:687-688. Abstract


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