Vomiting of Pregnancy (Morning Sickness) & Hyperemesis Gravidarum (Pernicious Vomiting of Pregnancy)


Essentials of Diagnosis

  • Morning or evening nausea and vomiting.
  • Persistent vomiting severe enough to result in
  • weight loss, dehydration, starvation ketosis, hypochloremic alkalosis, hypokalemia.
  • May have transient elevation of liver enzymes.
  • Appears related to high or rising serum hCG.
  • More common with multiple gestation or hydatidiform mole.

General Considerations

Nausea and vomiting begin soon after the first missed period and cease by the fifth month of gestation. Up to three-fourths of women complain of nausea and vomiting during early pregnancy, with the vast majority noting nausea throughout the day. This problem exerts no adverse effects on the pregnancy and does not presage other complications.

Persistent, severe vomiting during pregnancy - hyperemesis gravidarum - can be disabling and require hospitalization. Thyroid dysfunction can be associated with hyperemesis gravidarum, so it is advisable to determine TSH and free T4 values in these patients.


A. Mild Nausea and Vomiting of Pregnancy
Reassurance and dietary advice are all that is required in most instances. Because of possible teratogenicity, drugs used during the first half of pregnancy should be restricted to those of major importance to life and health. Antiemetics, antihistamines, and antispasmodics are generally unnecessary to treat nausea of pregnancy. Vitamin B6 (pyridoxine), 50-100 mg/d orally, is nontoxic and may be helpful in some patients.

B. Hyperemesis Gravidarum
Hospitalize the patient in a private room at bed rest. Give nothing by mouth for 48 hours, and maintain hydration and electrolyte balance by giving appropriate parenteral fluids and vitamin supplements as indicated. Rarely, total parenteral nutrition may become necessary. As soon as possible, place the patient on a dry diet consisting of six small feedings daily plus clear liquids 1 hour after eating. Prochlorperazine rectal suppositories may be useful. After in-patient stabilization, the patient can be maintained at home even if she requires intravenous fluids in addition to her oral intake.

Goodwin TM et al: Understanding and treating nausea and vomiting of pregnancy. Sponsored by NICHD. Am J Obstet Gynecol 2002;186(Suppl 5):S181.

Lacroix R et al: Nausea and vomiting during pregnancy: a prospective study of its frequency, intensity, and patterns of change. Am J Obstet Gynecol 2000;182:931.

Provided by ArmMed Media
Revision date: July 6, 2011
Last revised: by Janet A. Staessen, MD, PhD