ACOG Guidelines at a Glance: Nausea and Vomiting of Pregnancy
COMMITTEE ON PRACTICE BULLETINS—OBSTETRICS
Practice Bulletin No. 153: Nausea and vomiting of pregnancy. September 2015. American College of Obstet Gynecol 2015;126:e12-24. Full text of ACOG Practice Bulletins is available to ACOG members at www.acog.org/Resources-and-Publications/Practice-Bulletins/Committee-in-Practice-Bulletins-Obstetrics/Nausea-and-Vomiting-of-Pregnancy
NAUSEA AND VOMITING OF PREGNANCY Nausea and vomiting of pregnancy is a common condition that affects the health of the pregnant woman and her fetus. It can diminish the woman’s quality of life and also significantly contributes to health care costs and time lost from work (1,2). Because “morning sickness” is common in early pregnancy, the presence of nausea and vomiting of pregnancy may be minimized by obstetricians, other obstetric providers, and pregnant women and, thus, undertreated (1). Furthermore, some women do not seek treatment because of concerns about safety of medications (3). Once nausea and vomiting of pregnancy progresses, it can become more difficult to control symptoms; treatment in the early stages may prevent more serious complications, including hospitalization (4). Mild cases of nausea and vomiting of pregnancy may be resolved with lifestyle and dietary changes, and safe and effective treatments are available for more severe cases. The woman’s perception of the severity of her symptoms plays a critical role in the decision of whether, when, and how to treat nausea and vomiting of pregnancy. The purpose of this document is to review the best available evidence about the diagnosis and management of nausea and vomiting of pregnancy.
A common condition of pregnancy with potential for costly medical management and significant psychosocial and medical morbidity
By Haywood L Brown, MD
Haywood L Brown, MD, is F. Bayard Carter Professor and Chair, Obstetrics and Gynecology, Duke University, Durham, North Carolina. He is also a member of the editorial board of Contemporary OB/GYN.
Nausea and vomiting is an expectation for the majority of women during the first trimester of pregnancy. In fact, only 25% of pregnancies are unaffected by nausea with or without vomiting. Among affected woman, subsequent pregnancies have a recurrence of 15.2% to 81%.1 The etiology is unknown but there are various theories including: psychologic predisposition, evolutionary adaptation to protect the woman and fetus from potentially dangerous foods, and the hormonal stimulus of high human chorionic gonadotropin (HCG) and estradiol levels in early pregnancy. Conditions with increased placental mass such as molar pregnancy and multiple gestations are associated with a higher risk for nausea and vomiting.
The severity of symptoms is variable from patient to patient and they typically peak by 9 weeks. With early treatment and dietary counseling, the severity of symptoms diminishes as gestation advances; for most women, symptoms abate or resolve by the end of the first trimester. However, for some women, the condition is severe and progresses to hyperemesis gravidarum, which occurs in 0.3 to 3% of pregnancies.2 Certain clinical criteria should be met in to define this extreme form of nausea and vomiting. These include persistent nausea and vomiting not caused by other underlying medical conditions, ketonuria as a measure of acute starvation, and at least a 5% weight loss from the pre-pregnancy weight. Hyperemesis is the most common reason for obstetrical triage visits and hospital admission in the first half of pregnancy and significantly impacts psychosocial well-being, loss of productivity, and quality of life.
Differential diagnosis is extensive for women who first experience nausea and vomiting after 9 weeks’ gestation, as seen in Table 1 of Practice Bulletin 153.3 History predating the pregnancy is important especially for the gastrointestinal conditions cholelithiasis or peptic ulcer disease, or metabolic endocrine conditions involving the thyroid or parathyroid, or diabetes. Symptoms of fever or abdominal pain should also prompt an investigation for other causes in the differential because neither are typical features of hyperemesis. Abnormal laboratory findings in hyperemesis can include mildly elevated liver transaminase and bilirubin, elevated amylase, and suppressed thyroid stimulating hormone (TSH) levels.