Evidence-Based Approaches to Managing Nausea and Vomiting in Early Pregnancy

Tekoa L. King, CNM, MPH; Patricia Aikins Murphy, CNM, DrPH


J Midwifery Womens Health. 2009;54(6):430-444. 

In This Article

Abstract and Introduction


Nausea and vomiting in pregnancy is a continuum that ranges from mild discomfort to significant morbidity. Systematic assessment with the use of the Pregnancy-Unique Quantification of Emesis/Nausea (PUQE) index and timely treatment using evidence-based protocols can decrease the time that many women spend using treatment recommendations that are inadequate. This article reviews the epidemiology of nausea and vomiting in pregnancy, use of the PUQE index, and the evidence for specific nonpharmacologic and pharmacologic treatment regimens. A protocol for clinical management is presented.


Nausea and vomiting are among the cardinal signs of early pregnancy, recognized as such since at least the time of Hippocrates. In contemporary Western societies, an estimated 50% to 80% of pregnant women experience nausea and/or vomiting during the first trimester of pregnancy.[1,2] The problem is generally time-limited, with onset about the fifth week after the last menstrual period (LMP), a peak at 8 to 12 weeks, and resolution by 16 to 18 weeks for most women; approximately 5% of women will have symptoms throughout pregnancy.[3] Although commonly termed "morning sickness," only 17% of women report being affected only in the morning.[4] In a prospective study in which 160 women provided daily diaries in early pregnancy, 74% reported nausea with a mean duration of 34.6 days, "morning sickness" occurred in only 1.8%, and 80% reported nausea lasting all day. Only half of women reported relief by 14 weeks, but 90% had relief by 22 weeks.[5]

The most severe manifestations of nausea and vomiting of pregnancy (NVP) result in hyperemesis gravidarum (HG). Although there is no standard definition of HG, most diagnostic criteria include: persistent vomiting before 9 weeks after the LMP, weight loss >5% of initial body weight, electrolyte imbalance (hypokalemia), and dehydration and/or ketonuria.[6] Severe HG symptoms are the second most common reason for prenatal hospitalizations in the United States (11.4% of all nondelivery antenatal admissions).[7] Risk factors for HG include: clinical hyperthyroid disorders, prepregnancy psychiatric diagnosis, previous pregnancy complicated by HG, molar pregnancy, multiple gestation with a male and female fetus, diabetes, and gastrointestinal disorders. Women 30 years of age and older and women who smoke have a lower risk of HG.[6,8]

Quality of life (QOL) and work efficiency are adversely affected by NVP for women who have these symptoms.[2,9] Fifty percent of women say NVP affects their ability to work, as many as 35% require time off from jobs (mean, 62 hours), 50% say it affects their relationships with family and partners, and 55% report being depressed.[9,10] When QOL measures are used in research studies, the scores for women with NVP are worse than the scores of women who report chronic depression.[11] More than 80% of women with HG who responded to a recent survey stated that NVP caused adverse psychosocial effects, including concerns about economics and employment, depression, anxiety, and fear about future pregnancies.[12] Among women with severe NVP or HG, 76% changed plans for future children, 15% terminated pregnancy secondary to HG, and 7% reported long-term psychological sequelae.[13] A 2002 study estimated reduced productivity, visits to health care professionals, and the cost of medications and other remedies at $2947 per woman with moderate to severe NVP.[11]

Conversely, nausea in pregnancy is sometimes a positive sign. The absence of nausea is one of the factors associated with spontaneous miscarriage.[14] Because there is a close temporal relationship between NVP and beta-human chorionic gonadotropin (β-hCG) levels, some have theorized that nausea-associated nutrient restriction during early pregnancy may be beneficial to fetal and placental development.[15] Nonetheless, given the widespread prevalence of NVP, potential severity, and adverse effects on QOL, pregnant women and their providers need treatments that are effective yet safe to use during the period of embryonic and early fetal development. This article provides an evidence-based review of effective and safe treatments for NVP.


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