Many women have problems with nausea and sometimes vomiting (morning sickness) during the first 16 weeks of pregnancy. For some women, morning sickness may be one of the first signs of pregnancy. The term "morning sickness" can be misleading, because symptoms can occur at any time of the day. The causes of morning sickness are not fully understood, but hormone changes that occur during pregnancy may play a role.

Morning sickness usually goes away as a pregnancy progresses. While many women feel better after the first trimester, some report ongoing nausea or vomiting through the second trimester. You may be able to gain some relief from morning sickness using home treatment, such as drinking tea. Talk to your doctor about safe medicines to treat your nausea and vomiting.

Vomiting during pregnancy is more likely to be serious if the vomiting is moderate to severe (occurs more than 2 to 3 times per day) or is accompanied by lower abdominal (pelvic) pain or vaginal bleeding. These symptoms may be caused by an infection, ectopic pregnancy, miscarriage, or some other serious problem.

If you have severe, ongoing nausea and vomiting (hyperemesis gravidarum), see your doctor for treatment. This uncommon complication of pregnancy can lead to dehydration. You may need prescribed medicines, hospitalization, or both.

Be sure to watch for signs of dehydration if vomiting develops. Even mild dehydration can affect other problems, such as constipation or heartburn, that may occur during pregnancy.

Symptoms of mild dehydration include the following:

• You may be more thirsty than usual.
• Your urine may be darker than usual.

Symptoms of moderate dehydration include the following:

• You may be a lot more thirsty than usual.
• Your mouth and eyes may be drier than usual.
• Your urine may be much darker than usual.
• You may pass little or no urine for 8 or more hours.
• You may feel dizzy when you stand or sit up.

Symptoms of severe dehydration include the following:

• Your mouth and eyes may be extremely dry.
• You may pass little or no urine for 12 or more hours.
• You may not feel alert or be able to think clearly.
• You may be too weak or dizzy to stand.
• You may pass out.

Call your doctor if:

• You have symptoms of moderate dehydration.
• Vomiting is so severe that you are not able to drink fluids.
• Your vomiting has not gotten better with home treatment.

Practice the following good health habits until you see your health professional:

• Eat a balanced diet.
• Do not smoke.
• Do not use alcohol or drugs.
• Avoid caffeine or limit your intake to about 1 cup of coffee or tea each day.
• Do not clean a cat litter box.
• Avoid people who are ill.