Hyperemesis Gravidarum

Course #33175 - $30-


Study Points

  1. Define hyperemesis gravidarum, and distinguish it from the normal nausea and vomiting of pregnancy.
  2. List the potential effects of hyperemesis gravidarum on the fetus and mother.
  3. Compare the various theories of etiology of hyperemesis gravidarum.
  4. Identify the populations at risk for hyperemesis gravidarum.
  5. Describe dietary interventions for treatment of hyperemesis gravidarum.
  6. Describe pharmacologic agents used in the management of hyperemesis gravidarum.
  7. Describe the role of intravenous therapy in treating hyperemesis gravidarum.
  8. Outline nonpharmacologic interventions to treat hyperemesis gravidarum.
  9. Explain the nursing assessment and related diagnosis and interventions for the patient with hyperemesis gravidarum.

    1 . What percentage of pregnant patients suffer from hyperemesis gravidarum?
    A) 0.2% to 3.6%
    B) 4.0% to 6.2%
    C) 10% to 12%
    D) 10% to 20%

    INTRODUCTION

    Between 50% and 80% of pregnant patients experience nausea and vomiting beginning at about the 4th week and ending at about the 12th week of gestation [1,10]. In fact, nausea and vomiting are considered a presumptive sign of early pregnancy, and for 10% to 20% of pregnant patients, these symptoms may persist throughout the whole pregnancy. While nausea and vomiting are common occurrences, hyperemesis gravidarum is rare, occurring in 1% to 3% of all pregnancies [1,10,53,127].

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    2 . Which of the following is part of the definition of hyperemesis gravidarum?
    A) Vomiting that persists for the entire pregnancy
    B) Vomiting upon arising more than five days per week
    C) Vomiting that appears after the 20th week of pregnancy
    D) Severe nausea and vomiting with weight loss greater than 5% of prepregnancy body weight

    DEFINITION OF HYPEREMESIS GRAVIDARUM

    There is some variation in the literature as to the exact definition of hyperemesis gravidarum. It has been described as intractable nausea and vomiting during pregnancy severe enough to require hospitalization [4,115]. The condition appears during the first trimester and is unassociated with other medical conditions, such as cholestasis, hepatitis, pre-eclampsia, viral syndromes, Ménière disease, or influenza.

    Hyperemesis gravidarum is a severe form of nausea and vomiting in pregnancy associated with significant impairment of oral intake and daily functioning. It may result in dehydration, electrolyte abnormalities, nutritional deficiencies and weight loss and can substantially affect physical and psychological well-being [4]. Many patients require hospitalization in order to control the symptoms [5,115]. In most cases, the onset of symptoms is between 4 and 10 weeks' gestation and the symptoms usually (but not always) subside by 20 weeks' gestation. Clinically, practitioners commonly treat nausea and vomiting in early pregnancy, regardless of whether the patient fits all the criteria of a diagnosis of hyperemesis gravidarum.

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    3 . Which of the following statements regarding the effects of hyperemesis gravidarum on the fetus is FALSE?
    A) Hip dysplasia has been linked to hyperemesis gravidarum.
    B) Normal nausea and vomiting appear to be protective in the first trimester.
    C) There is evidence that hyperemesis gravidarum is associated with high infant birth weight.
    D) Infants born to individuals with hyperemesis gravidarum tend to have significantly lower birth weights.

    EFFECTS OF HYPEREMESIS GRAVIDARUM

    It has been suggested that hyperemesis gravidarum may be associated with low infant birth weight, likely related to maternal nutritional (i.e., weight) maintenance [6,7,8]. Researchers have found a modest association between severe nausea and vomiting in pregnancy and intrauterine growth restriction and low infant birth weight [6]. A maternal weight loss of greater than 5% seems to be the critical factor in fetal growth restriction. However, even insufficient weight gain can have negative repercussions. A weight gain of less than 7 kg (15.4 pounds) during the duration of pregnancy is associated with low birth weight and preterm births [5,7,115,119].

    There also appears to be a correlation between severe hyperemesis during pregnancy and impaired insulin sensitivity in offspring [9]. In one study of healthy children (4 to 11 years of age) who were born at term to mothers who were admitted to hospital with severe hyperemesis gravidarum during their pregnancy, the offspring of the patients with hyperemesis had 20% lower insulin sensitivity compared to children of healthy individuals. Longer term follow-up studies are necessary to determine if this difference persists into adulthood.

    One study found an increased risk for psychological and behavioral problems in adult offspring of pregnancies affected by hyperemesis [10]. Adult offspring exposed to hyperemesis in utero reported higher likelihood of depression, anxiety, and bipolar disorder diagnoses.

    Various studies have linked a greater risk for birth defects, developmental delays, and serious health problems (e.g., type 2 diabetes, hypertension, high cholesterol, and cardiovascular disease) with maternal hyperemesis gravidarum [8,11]. One small Japanese study found impaired fetal head growth was associated with lower maternal weight gain from the lowest body weight to weight at 20 weeks' gestation [129]. The authors hypothesize that this could affect fetal brain growth and development. Other potential fetal complications include [12,13]:

    • Shorter length

    • Undescended testes

    • Testicular cancer

    • Behavioral/emotional problems

    • Integumentary abnormalities

    • Neurodevelopmental sequelae

    • Congenital heart disease

    • Neural tube defects

    • Hip dysplasia

    • Perinatal death

    Despite the fact that hyperemesis gravidarum may be associated with poor fetal growth and outcome, a large, epidemiologic study found that the likelihood of miscarriage was 70% lower in those who experienced normal nausea and vomiting early in pregnancy [14]. More severe sickness was associated with a greater decrease in the risk of miscarriage. This finding supports the belief that normal nausea and vomiting in the first trimester of pregnancy may be protective against miscarriage [14,15]. This may be a result of robust placental synthesis in a healthy pregnancy [92].

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    4 . Thiamine (vitamin B1) deficiency results in which potential maternal complication of hyperemesis gravidarum?
    A) Renal failure
    B) Esophageal rupture
    C) Wernicke encephalopathy
    D) Osmotic demyelination syndrome

    EFFECTS OF HYPEREMESIS GRAVIDARUM

    Wernicke encephalopathy results from a deficiency of thiamine (vitamin B1) and is manifested by confusion, gait ataxia, ophthalmoplegia (paralysis of the eye muscles), or convulsions. Typically, thiamine is initially lost by prolonged vomiting. When intravenous fluid replacement containing dextrose is given, the body's metabolism of the dextrose quickly consumes the remaining thiamine. Therefore, the cause is usually not the hyperemesis itself but is instead due to fluid replacement without thiamine supplementation. Although the condition is very rare, it is associated with a high mortality rate (20%) [16,130].

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    5 . Which of the following gestational hormones is hypothesized to be correlated with hyperemesis gravidarum?
    A) Estrogen
    B) Testosterone
    C) Human placental lactogen (HPL)
    D) Human chorionic gonadotropin (hCG)

    ETIOLOGY AND PATHOPHYSIOLOGY

    Human chorionic gonadotropin has been suspected as the cause of hyperemesis gravidarum based chiefly on the observation that its peak concentration in pregnancy coincides with the peak of nausea and vomiting [32]. Another suggestion for the causative role of hCG in persistent nausea and vomiting is the association between increased hCG concentrations and hyperemesis gravidarum in cases of twin and molar pregnancies.

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    6 . Which of the following bacteria has been investigated as a cause of hyperemesis gravidarum?
    A) Shigella
    B) Helicobacter pylori
    C) Staphylococcus aureus
    D) Group B streptococcus

    ETIOLOGY AND PATHOPHYSIOLOGY

    Infection with Helicobacter pylori, a gram-negative spiral bacterium strongly associated with peptic ulcers, has been investigated as a cause of hyperemesis gravidarum. In one study, the investigators found that 89% of pregnant patients with hyperemesis gravidarum were seropositive for H. pylori, compared to 30% of the control group [44]. A 2010 study reached a similar conclusion, finding that 87% of women with hyperemesis gravidarum were infected with H. pylori, compared to 32% without the condition [45]. A meta-analysis of 38 cross-sectional and case-control studies, involving 10,289 patients, revealed a significant association between H. pylori infection and hyperemesis gravidarum [121]. As such, screening of H. pylori infection should be added to the investigation of hyperemesis gravidarum cases. IgG antibody testing may detect H. pylori infection in patients presenting with hyperemesis; post-eradication monitoring may be carried out by stool antigen testing. Eradication of H. pylori in pregnant patients can significantly improve symptoms. Treatment options include the utilization of triple therapy, consisting of a proton-pump inhibitor and two antibiotics (e.g., amoxicillin or erythromycin and metronidazole) for two weeks [121]. Several case reports have suggested that eliminating H. pylori infection may cure hyperemesis gravidarum or at least modify its course [44,46,47].

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    7 . Which of the following conditions increases the risk of hyperemesis gravidarum?
    A) Multiparity
    B) Cigarette smoking
    C) High prepregnancy body weight
    D) Maternal age older than 35 years

    POPULATIONS AT RISK

    High prepregnancy body weight and nulliparity (having not given birth to a child) have been cited as risk factors for hyperemesis, and as discussed, a high-fat diet has been found to greatly increase the odds [4,63]. Maternal age younger than 20 years and twin gestation are also noted as risk factors [4]. The condition can repeat itself in subsequent pregnancies and is more common in patients with a history of spontaneous abortions [13]. Trogstad et al. found that if an individual experienced hyperemesis in her first pregnancy, there was a 15.2% risk that she would experience it in subsequent pregnancies [64]. Those never having suffered from the condition have a 0.7% risk in later pregnancies.

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    8 . Which of the following statements is TRUE regarding demographic data related to hyperemesis gravidarum?
    A) Hispanic individuals have the lowest incidence.
    B) Native Americans have the highest incidence.
    C) Asian Americans have a significantly higher incidence.
    D) There is limited evidence that any racial or ethnic group is at increased risk.

    POPULATIONS AT RISK

    There are limited demographic data relating to hyperemesis gravidarum, but some (also limited) evidence suggests a higher rate among certain racial/ethnic minority groups [67]. One study did note an increased risk among Pacific Islander patients [68]. Inuit and Native American populations tend to have a lower incidence of hyperemesis gravidarum [10]. In a study of 67 women with hyperemesis presenting at Los Angeles Women's Hospital, 94% were Hispanic [23]. However, the authors did not evaluate the racial mix of the general population served by this facility. Several studies have shown no clear racial predominance for hyperemesis gravidarum [10]. A large study of 417,028 pregnancies in England showed a statistical predominance in Asian and Black patients [118,119].

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    9 . Nurses should make which of the following recommendations regarding prenatal vitamins to the patient with hyperemesis gravidarum?
    A) Take prenatal vitamins after eating.
    B) Take prenatal vitamins before eating.
    C) Add an iron supplement to the prenatal vitamins.
    D) Stop taking prenatal vitamins containing iron until vomiting is resolved.

    INTERVENTION STRATEGIES

    Nausea and vomiting of pregnancy is usually initially treated conservatively with diet in the hopes that the problem will not progress to hyperemesis gravidarum. General recommendations include choosing a bland diet, increasing carbohydrate intake, decreasing fat intake, avoiding offensive food odors, and avoiding iron supplementation, if possible. Omitting prenatal vitamins containing iron until the nausea resolves may also be helpful.

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    10 . Which of the following dietary recommendations are effective in the management of hyperemesis gravidarum?
    A) Eating high-fat foods
    B) Drinking fluids with meals
    C) Removing salt from the diet
    D) Eating small, frequent meals

    INTERVENTION STRATEGIES

    Specific suggestions are to eat bread or crackers before getting out of bed in the morning, when nauseated, and before retiring for the night. Experts also recommend eating small meals every two to three hours; drinking liquids between meals rather than with meals to avoid gastric distention; eating low-fat, high-protein foods; avoiding fried foods; and salting food to taste.

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    11 . Which of the following statements about the management of hyperemesis gravidarum is FALSE?
    A) Psychological support should be included.
    B) Short-term steroid therapy may be indicated.
    C) Antiemetic therapy is rarely contraindicated.
    D) Total parental nutrition (TPN) may be needed.

    INTERVENTION STRATEGIES

    The antiemetic medications used to treat nausea and vomiting in pregnancy fall into two broad classes: antihistamines and phenothiazines. Despite evidence of safety to the fetus, most antiemetics are contraindicated in pregnancy.

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    12 . Which of the following statements regarding the use of Bendectin is FALSE?
    A) It was conclusively shown to be teratogenic.
    B) The individual ingredients in the formula have been available in over-the-counter and prescription forms.
    C) After its removal from the market, the incidence of limb deformities did not decrease.
    D) It was withdrawn from the market because of the manufacturer's fear of further lawsuits and the high cost of insurance.

    INTERVENTION STRATEGIES

    Among the antihistamines used by patients for nausea and vomiting during pregnancy is doxylamine in combination with pyridoxine hydrochloride (vitamin B6). It carries an FDA pregnancy Category B, which indicates that human fetal risk is relatively unlikely [76]. The FDA approved the combination of 10 mg doxylamine and 10 mg pyridoxine (marketed as Diclegis) in 2013 for the treatment of hyperemesis gravidarum. It is the only drug specifically approved for this indication and has become a first-line therapy [83,92]. A version of this combination that also included dicyclomine hydrochloride (marketed as Bendectin) was originally introduced in 1956 and was taken off the market in 1983 [86]. Despite the fact that controlled studies found no increased risk of birth defects, highly publicized lawsuits in the 1970s, involving neonates with severe malformations whose mothers had taken Bendectin, were judged unfavorably against the manufacturer. It is interesting to note that after Bendectin was removed from the market, the incidence of the type of limb deformities and congenital heart disease attributed to the medication did not decrease [86].

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    13 . Thiamine replacement is essential prior to initiating hydration therapy in the patient with hyperemesis gravidarum because
    A) severe anemia may occur.
    B) vomiting may be exacerbated.
    C) it may result in overhydration.
    D) dextrose causes the body to metabolize thiamine stores, which may result in Wernicke encephalopathy.

    INTERVENTION STRATEGIES

    Thiamine stores must be restored before intravenous therapy begins, as the dextrose in the solution causes the body to metabolize thiamine. As previously mentioned, thiamine deficiency can lead to Wernicke encephalopathy. Signs and symptoms of Wernicke encephalopathy include visual disturbances, such as diplopia or nystagmus, as well as disorientation, delusion, and gait ataxia. While there is no specific treatment regimen, some experts recommend parenteral thiamine 100–500 mg daily for three days and 2–3 mg per day thereafter [100].

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    14 . Which of the following is inappropriate for the patient receiving intravenous therapy for hyperemesis?
    A) Keeping the patient cool
    B) Monitoring intake and output
    C) Maintaining patency of the IV site
    D) Counseling the patient regarding diet

    INTERVENTION STRATEGIES

    Nursing assessments should include starting and maintaining the patency of the intravenous infusion, maintaining the infusion rate, and assessing the IV site for infection or infiltration. Venipuncture can be difficult in dehydrated patients, but placing the site in a dependent position and warming the area with warm compresses may cause enough vasodilatation to enable an easy insertion. Warming the first liter of fluid may prevent the feeling of coldness that dehydrated patients experience.

    Assessments might also include intake and output, as well as assessing for episodes of vomiting. Vital signs are one marker of hydration status and should be monitored per protocol. Antiemetic therapy is often initiated as well as IV hydration; therefore, ongoing assessments for side effects should be included.

    Shortly after IV therapy is initiated, oral feeding may be resumed. The diet is usually initiated with clear liquids and proceeds to small, frequent meals. Nurses should monitor dietary intake and advance the diet as tolerated. If the diet is not tolerated, enteral feeding may be an option [99].

    Discharge planning should be initiated on admission. The goal is to discharge the patient to home as soon as dehydration is treated, vomiting has subsided, and the patient is able to keep food down. Discharge planning should include counseling regarding diet, as well as educating the patient regarding her medications, side effects, and warning signs.

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    15 . Which alternative therapy has been best studied in the management of hyperemesis gravidarum?
    A) Ginger
    B) Hypnosis
    C) Acupressure
    D) Therapeutic touch

    INTERVENTION STRATEGIES

    Acupressure has been used for the treatment of morning sickness, as well as motion sickness and post-chemotherapy nausea and vomiting. As such, it is the best-studied alternative therapy. Treatment includes wearing wristbands that apply pressure to the inner forearm approximately three finger breadths proximal to the wrist (e.g., Sea-Bands). A 2014 Cochrane review did not find P6 acupuncture or acupressure wristbands significantly more effective than placebo for the treatment of nausea and vomiting in early pregnancy, but it is unclear if the approach would be more effective for patients with hyperemesis gravidarum [106]. While many clinical trials show statistically significant improvement in nausea, fewer studies show improvement in vomiting [90]. However, many of the studies are flawed, having small sample sizes, inadequate control groups, and little if any blinding [90].

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    16 . Which of the following signs and symptoms would the nurse expect to find in a patient with hyperemesis gravidarum?
    A) Elevated pulse
    B) Ketotic breath smells
    C) Dry mucous membranes
    D) All of the above

    NURSING IMPLICATIONS

    On physical examination, the patient may appear weak, pale, and with dry mucous membranes. A ketotic breath smell may be noted. Infrequently, jaundice might be noted. A weight check may reveal weight loss, as much as 5 pounds in a week. Blood pressure may manifest orthostatic changes, and pulse may be elevated secondary to dehydration.

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    17 . Which of the following might the nurse find evidence of in a urine dipstick analysis in the patient with hyperemesis gravidarum?
    A) Ketonuria
    B) Glycosuria
    C) Proteinuria
    D) Albuminuria

    NURSING IMPLICATIONS

    A urine dipstick analysis should be performed, with particular attention to the presence of ketones. Specific gravity will be increased [109]. In its 2024 guideline, the Royal College of Obstetricians and Gynaecologists assert that urine ketone levels should not be used to determine the severity of hyperemesis gravidarum or guide fluid therapy, because ketonuria is not a reliable indicator of dehydration severity [53]. However, ACOG continues to recognize large ketonuria as a potential measure of acute starvation [92].

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    18 . According to the North American Nursing Diagnosis Association (NANDA), an appropriate nursing intervention for the patient with nausea is
    A) consuming fried or greasy foods.
    B) adding spices to foods while cooking.
    C) lying supine for 30 minutes after eating.
    D) drinking fluids in between small, frequent meals.

    NURSING IMPLICATIONS

    Nausea is defined as "a subjective unpleasant, wave-like sensation in the back of the throat, epigastrium, or abdomen that may lead to the urge or need to vomit" [111]. Olfactory stimulation can sometimes trigger nausea. Interventions include avoiding unpleasant odors and food smells, particularly those that trigger the nausea. The patient should avoid fried or greasy meals because these also promote nausea. The patient should attempt small, frequent meals and drink fluids in between meals to help reduce the amount of food in the stomach and avoid the feeling of fullness that can aggravate nausea. The patient should avoid lying supine for at least 30 minutes after eating, because this position applies pressure on the diaphragm and digestion is improved by gravity.

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    19 . If a patient with hyperemesis gravidarum is at risk for fluid volume deficit, nursing assessment may reveal
    A) hypertension.
    B) increased potassium.
    C) decreased hemoglobin.
    D) dry mucous membranes.

    NURSING IMPLICATIONS

    Dehydration is a state in which an individual is at risk for or experiencing fluid depletion. The nursing assessment may reveal dry mucous membranes, decreased skin turgor, tachycardia, hypotension, increased body temperature, and ketonuria. The hemoglobin and hematocrit may be elevated, but sodium, potassium, and chloride may be reduced due to vomiting.

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    20 . The diagnosis of impaired tissue integrity, especially in the oral mucous membranes, is due to
    A) vitamin E deficiency.
    B) dehydration and vomiting.
    C) breathing through the mouth.
    D) increased vitamin consumption.

    NURSING IMPLICATIONS

    This nursing diagnosis includes impaired oral mucous membrane integrity, due to both dehydration and vomiting. Nursing assessments might reveal a complaint of dry mouth, bad taste, or even excessive salivation. Inspection may reveal dry or cracked mucous membranes, pallor, ulcerations, edema, coated tongue, or hemangiomas (a network of small blood-filled capillaries near the surface of the skin).

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