During the first trimester of pregnancy, many women experience the bouts of nausea and vomiting known as morning sickness.

Despite its name, morning sickness can occur at any time, day or night. It usually begins around the 6th week of pregnancy, peaks around week 9, and disappears by weeks 16 to 18. Although unpleasant, morning sickness is considered a normal part of a healthy pregnancy.

But what's not normal is when morning sickness becomes so severe that a woman persistently vomits several times a day, loses weight, and becomes dehydrated or at risk for dehydration.

When this rare pregnancy-related condition is left untreated, it can interfere with a woman's health and her baby's ability to thrive.

About Severe Morning Sickness

The medical term for severe morning sickness is "hyperemesis gravidarum" (which means "excessive vomiting during pregnancy"). It usually follows a timeline that is similar to morning sickness; however, it often begins earlier in the pregnancy, between weeks 4 and 5, and lasts longer.

Although some women with severe morning sickness feel better about halfway through their pregnancy (around week 20), some continue to experience it throughout the entire pregnancy. Often, the symptoms become less severe as the pregnancy progresses.

Most of the time, hyperemesis gravidarum occurs during a woman's first pregnancy. Unfortunately, women who experience it in one pregnancy are more likely to experience it again in later pregnancies.

Causes

The cause of severe morning sickness is unknown. Research suggests that it might be related to hormonal changes that occur during pregnancy. Specifically, a hormone called human chorionic gonadotropin, or HCG, might be to blame because the condition primarily occurs when HCG is at its highest levels in a pregnant woman's body.

Severe morning sickness also might be hereditary because it is more common in women whose close family members (such as mothers and sisters) have had it.

Risk Factors

Certain factors can increase a woman's chances of having severe morning sickness during pregnancy. In addition to having a personal or family history of the condition, the following can put a woman at risk:

• carrying multiples (twins, triplets, etc.)
• history of motion sickness
• migraine headaches with nausea or vomiting

Effects

The nausea and vomiting that happens in a case of severe morning sickness are so extreme that they can have harmful effects on both the mother and baby. The inability to keep down food makes it difficult for a woman to meet her nutritional needs. As a result, she might lose weight. And a loss of fluids, combined with the loss of stomach acid that occurs during vomiting, also can cause dehydration and electrolyte imbalances.

If a woman does not receive treatment, it can cause many complications, including organ failure and the premature birth of her baby.

When to Call the Doctor

It's important to call the doctor right away if a pregnant woman has any of the following symptoms:

• nausea that persists throughout the day, making it impossible to eat or drink
• vomiting that occurs three to four times per day or an inability to keep anything in the stomach
• vomit that is a brownish color or has blood or streaks of blood in it
• weight loss
• fainting or dizziness
• decreased urination
• a rapid heart rate
• recurrent headaches
• unpleasant, fruity mouth or body odor
• extreme fatigue
• confusion

Treatment

Although treatments that are commonly used for morning sickness, such as eating dry crackers in the morning or consuming a bland diet, may be recommended for women with extreme morning sickness, they may not be effective on their own because of the severity of the condition.

Medical treatment may include:

• a short period of not eating by mouth to rest the gastrointestinal system
• intravenous (IV) fluids
• vitamin and nutritional supplements

If necessary, the woman might also receive medication to stop the vomiting, either by mouth or through an IV. The doctor might recommend eating foods with ginger or taking vitamin B6 supplements to help alleviate nausea. The following can also help:

• consuming a bland diet
• eating frequent small meals
• drinking plenty of fluids when not feeling nauseated
• avoiding spicy and fatty foods
• eating high-protein snacks
• avoiding sensory stimuli that can act as triggers

Additionally, if a woman is feeling anxious or depressed as a result of her condition, talking to a therapist or counselor might help her cope with her feelings.

Outlook

With treatment, a woman with a case of severe morning sickness can feel better and receive the nourishment she needs to help her and her baby thrive. And lifestyle changes can help to minimize nausea and vomiting and make the pregnancy more enjoyable.

With time, symptoms usually do improve, and — of course — resolve completely by the beginning of a woman's next miraculous journey: parenthood.

Reviewed by: Larissa Hirsch, MD
Date reviewed: April 2011