Hyperemesis Gravidarum

Unlike the transient nausea and vomiting normally experienced until about the 12th week of pregnancy, hyperemesis gravidarum is severe and unremitting nausea and vomiting that persists after the first trimester. It usually occurs with the first pregnancy and commonly affects pregnant women with conditions that produce high levels of human chorionic gonadotropin, such as hydatidiform mole or multiple pregnancy.

This disorder occurs among blacks in about 7 in 1,000 pregnancies and among whites in about 16 in 1,000 pregnancies. The prognosis is good.

Causes

Several factors may contribute to hyperemesis gravidarum, including:

• High or rapidly rising serum levels of hormones such as hCG (human chorionic gonadotropin)secreted by the fetus.
• Increased estrogen levels
• Pressure on the stomach and intestines
• a multiple pregnancy (i.e., twins or more)
• hydatidiform mole

Signs and Symptoms

The patient typically complains of unremitting nausea and vomiting, the cardinal symptoms of hyperemesis gravidarum. The vomitus initially contains undigested food, mucus, and small amounts of bile; later, it contains only bile and mucus; and finally, blood and material that resembles coffee grounds. The patient may report substantial weight loss and eventual emaciation caused by persistent vomiting, thirst, hiccups, oliguria, vertigo, and headache.

Inspection may reveal pale, dry, waxy, and possibly jaundiced skin, with decreased skin turgor; a dry and coated tongue; subnormal or elevated temperature; rapid pulse; and a fetid, fruity breath odor from acidosis. The patient may appear confused and delirious. Lassitude, stupor and, possibly, coma may occur.

Diagnostic tests

Diagnosis is used to rule out other disorders, such as gastroenteritis, cholecystitis, and peptic ulcer, which produce similar clinical effects. Differential diagnosis also rules out hydatidiform gestation, hepatitis, inner ear infection, food poisoning, emotional problems, and eating disorders.

The following test results support a diagnosis of hyperemesis gravidarum:

• Serum analysis shows decreased protein, chloride, sodium, and potassium levels and increased blooc urea nitrogen levels.
• Other laboratory tests reveal ketonuria, slight proteinuria, elevated hemoglobin levels, and an elevated white blood cell count

Treatment

The patient with hyperemesis gravidarum may require hospitalization to correct electrolyte imbalance and prevent starvation. I.V. infusions are used to maintain nutrition until she can tolerate oral feedings. She progresses slowly to a clear liquid diet, then a full liquid diet, and finally, small, frequent meals of high-protein solid foods. A midnight snack helps stabilize blood glucose levels.

Parenteral vitamin supplements and potassium replacements help correct deficiencies.

When persistent vomiting jeopardizes health, antiemetic medications are administered. Currently only meclizine and diphenhydramine are known to have a low risk for teratogenicity.

When vomiting stops and electrolyte balance has been restored, the pregnancy usually continues without recurrence of hyperemesis gravidarum. Most patients feel better as they begin to regain normal weight, but some continue to vomit throughout the pregnancy, requiring extended treatment. If appropriate, some patients may benefit from consultations with clinical nurse specialists, psychologists, or psychiatrists.

Prevention

Many of the conditions that lead to hyperemesis are not preventable and it is unknown why some women without those conditions develop hyperemesis. You can try to reduce your nausea during pregnancy by:

• Avoiding smells, foods or other things that stimulate nausea
• Eat frequent small meals
• Do not allow yourself to get too hungry or too full