Nausea and Vomiting of Pregnancy JEFFREY D. QUINLAN, LCDR, MC, USN, Naval Hospital, Jacksonville, Florida D. ASHLEY HILL, M.D., Florida Hospital, Orlando, Florida Nausea and vomiting of pregnancy, commonly known as “morning sickness,” affects approximately 80 percent of pregnant women. Although several theories have been pro- posed, the exact cause remains unclear. Recent research has implicated Helicobacter pylori as one possible cause. Nausea and vomiting of pregnancy is generally a mild, self-limited condition that may be controlled with conservative measures. A small percentage of preg- nant women have a more profound course, with the most severe form being hyperemesis gravidarum. Unlike morning sickness, hyperemesis gravidarum may have negative impli- cations for maternal and fetal health. Physicians should carefully evaluate patients with nonresolving or worsening symptoms to rule out the most common pregnancy-related and nonpregnancy-related causes of severe vomiting. Once pathologic causes have been ruled out, treatment is individualized. Initial treatment should be conservative and should involve dietary changes, emotional support, and perhaps alternative therapy such as gin- ger or acupressure. Women with more complicated nausea and vomiting of pregnancy also may need pharmacologic therapy. Several medications, including pyridoxine and doxy- lamine, have been shown to be safe and effective treatments. Pregnant women who have severe vomiting may require hospitalization, orally or intravenously administered corti- costeroid therapy, and total parenteral nutrition. (Am Fam Physician 2003;68:121-8. Copy- right© 2003 American Academy of Family Physicians.) See page 18 for defi- ausea and vomiting of preg- and weight loss (more than 5 percent of body nitions of strength-of- nancy begins between the weight). Multiple gestation, gestational tropho- evidence levels. fourth and seventh week after blastic disease, triploidy, trisomy 21 syndrome the last menstrual period in (Down syndrome), and hydrops fetalis have 80 percent of pregnant women been associated with an increased incidence of Nand resolves by the 20th week of gestation in all hyperemesis gravidarum.5 but 10 percent of these women.1 The condition has been shown to be more common in urban Etiology and Pathophysiology women than in rural women.2 One study3 The etiology of nausea and vomiting of identified increased risk in housewives and pregnancy remains unknown, but a number decreased risk in “white collar” or professional of possible causes have been investigated. white women who consumed alcohol before Although many physicians were taught conception, and in women over 35 years of age that psychologic factors are responsible for with a history of infertility. nausea and vomiting of pregnancy and Hyperemesis gravidarum, a severe form of hyperemesis gravidarum, few data support nausea and vomiting, affects one in 200 preg- this theory. In one well-known study,4 the nant women.4 Although the definition of this Cornell Medical Index was administered condition has not been standardized, accepted to 44 pregnant women with hyperemesis and clinical features include persistent vomiting, 49 pregnant women without hyperemesis; the dehydration, ketosis, electrolyte disturbances, Minnesota Multiphasic Personality Inventory (MMPI) was administered only to the preg- nant women with hyperemesis. The MMPI Few data support the theory that psychologic factors are data suggested that women with hyperemesis have hysteria, excessive dependence on their responsible for nausea and vomiting of pregnancy. The roles of mothers, and infantile personalities. However, human chorionic gonadotropin and estrogen are controversial. the study findings were not conclusive because comparative testing was not performed. JULY 1, 2003 / VOLUME 68, NUMBER 1 www.aafp.org/afp AMERICAN FAMILY PHYSICIAN 121 Gastrointestinal tract dysfunction also has with hyperemesis have suppressed thyrotropin- been suggested as a cause of nausea and vom- stimulating hormone (TSH) levels. Work is iting of pregnancy. In one study6 in which ongoing to elucidate the interaction of hCG and progesterone was prescribed to nonpregnant TSH in pregnant women with hyperemesis.5 women, resultant nausea and vomiting sug- A recent study10 suggested that chronic gested that delayed gastric motility caused by infection with Helicobacter pylori may play a progesterone may be responsible for the condi- role in hyperemesis gravidarum. In this study, tion. Another study7 reviewed many potential 61.8 percent of pregnant women with hyper- gastrointestinal causes of nausea and vomiting emesis were found to be positive for the of pregnancy, including abnormalities of gas- H. pylori genome, compared with 27.6 percent tric electrical rhythm (gastric dysrhythmias). of pregnant women without hyperemesis. Many reports have suggested that hormones may cause nausea and vomiting of pregnancy Differential Diagnosis and Evaluation and hyperemesis gravidarum. In one compara- A thorough history and a complete physical tive study,8 women with nausea and vomiting of examination are important in the evaluation of pregnancy were found to have elevated levels of pregnant women who present with persistent human chorionic gonadotropin (hCG); how- vomiting. Nausea and vomiting in early preg- ever, another study9 did not support this find- nancy is usually a self-limited condition. When ing. Some studies have shown elevated estrogen the condition is more severe, potentially serious levels in women with this condition; others have causes need to be ruled out (Table 1).5 If nausea not.7 Hence, the roles of hCG and estrogen and vomiting begin after nine weeks of gesta- remain controversial. Many pregnant women tion, other causes should be investigated. If the findings of the history and physical examination suggest a specific cause, testing is TABLE 1 directed toward confirming that cause. For Differential Diagnosis of Persistent Vomiting in Pregnancy example, the findings may suggest pyelo- nephritis, a common condition in pregnancy. Gastrointestinal disorders Metabolic disorders Ultrasonography may be helpful in ruling out Gastroenteritis Diabetic ketoacidosis gallbladder, liver, and kidney disorders. In Biliary tract disease Porphyria addition to hyperemesis gravidarum, preg- Hepatitis Addison’s disease nancy-related causes of persistent vomiting Intestinal obstruction Hyperthyroidism include acute fatty liver and preeclampsia. Peptic ulcer disease Neurologic disorders Nonpregnancy-related causes include gas- Pancreatitis Pseudotumor cerebri trointestinal, genitourinary, metabolic, and Appendicitis Vestibular lesions neurologic disorders. Genitourinary tract disorders Migraine headaches Pyelonephritis Central nervous system tumors Maternal and Fetal Outcomes Uremia Pregnancy-related conditions Women with uncomplicated nausea and Degenerating uterine leiomyoma Nausea and vomiting of pregnancy* vomiting of pregnancy (“morning sickness”) Torsion Acute fatty liver of pregnancy have been noted to have improved pregnancy Kidney stones Preeclampsia outcomes, including fewer miscarriages, pre- Drug toxicity or intolerance term deliveries, and stillbirths, as well as fewer instances of fetal low birth weight, growth *—Including hyperemesis gravidarum. retardation, and mortality.11,12 In contrast, Adapted with permission from Goodwin TM. Hyperemesis gravidarum. Clin hyperemesis gravidarum has been associated Obstet Gynecol 1998;41:597-605. with increases in maternal adverse effects, including splenic avulsion, esophageal rup- 122 AMERICAN FAMILY PHYSICIAN www.aafp.org/afp VOLUME 68, NUMBER 1 / JULY 1, 2003 Nausea and Vomiting of Pregnancy ture, Mallory-Weiss tears, pneumothorax, peripheral neuropathy, and preeclampsia, as Nonpharmacologic measures for treating nausea and vomiting well as increases in fetal growth restriction and of pregnancy include dietary changes, emotional support, mortality.13-15 and acupressure. Treatment The management of nausea and vomiting of pregnancy depends on the severity of the domestic violence is suspected, or evidence of symptoms. Treatment measures range from substance abuse or psychiatric illness exists. dietary changes to more aggressive approaches Acupressure. Several studies17,18 have sug- involving antiemetic medications, hospitaliza- gested acupressure as a treatment for nausea. tion, or even total parenteral nutrition (TPN). The most common location for acupressure is We prefer to start with dietary changes and the pericardium 6 or Neiguan point, which then add medications as necessary. A Cochrane is located three fingerbreadths above the wrist review of various nonpharmacologic and phar- on the volar surface.Various commercial prod- macologic treatments for nausea and vomiting ucts for relieving motion sickness (e.g., Sea- of pregnancy and hyperemesis gravidarum was Band, ReliefBand) apply pressure to this area. recently published.16 [Evidence level B, system- One review19 of data from seven trials involv- atic review of variable-quality randomized ing Neiguan point acupressure indicated that controlled trials (RCTs)] these products are helpful for controlling morning sickness in early pregnancy; how- NONPHARMACOLOGIC THERAPY ever, a recent study20 demonstrated no benefit Dietary Measures. Initial treatment of for acupressure in pregnant women. women with mild nausea and vomiting of Further data are necessary to determine pregnancy (i.e., morning sickness) should whether acupressure is a viable treatment for include dietary changes.