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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
