Facts on Morning Sickness (Vomiting During Pregnancy)
While you are pregnant, nausea and vomiting are common. A majority of women get mild to moderate symptoms during the first three months (first trimester) of pregnancy. These symptoms are usually gone by the fourth month.
Although this condition is often called morning sickness, most women have symptoms throughout the day.
Very rarely, a pregnant woman may experience a more serious condition involving severe vomiting, dehydration, and weight loss. This is called hyperemesis gravidarum.
What Causes Vomiting During Pregnancy?
The exact cause of nausea and vomiting in pregnancy is not clear. Most evidence points to rapid changes in hormone levels. These fluctuations may cause changes in the muscle contraction and relaxation patterns of your stomach and intestines, thus leading to nausea and vomiting.
The hormones that seem to have the most to do with this process include the pregnancy hormone human chorionic gonadotropin (hCG), estrogen, and progesterone. Abnormal levels of thyroid hormones have also been reported in women with severe vomiting, although a cause-and-effect relationship remains unclear. Some studies have shown that nausea is worse when your blood sugar level is low. Some researchers have found that women who are more likely to have nausea from birth control pills, migraines, or motion sickness are at higher risk for nausea and vomiting in pregnancy.
If you have a family history of hyperemesis gravidarum, you are more likely to have the condition. What causes hyperemesis gravidarum remains unknown despite active research.
The more popular theories fall into three areas:
- Hormonal: Elevated levels of human chorionic gonadotropin (hCG) or a component of this hormone may play a role in inducing vomiting. Thyrotoxicosis or hyperthyroidism is also believed to be associated with the condition. Another hormone thought to be involved is serotonin. Serotonin is a brain chemical that affects both the central nervous system and the gastrointestinal (GI) tract. These effects are believed to induce vomiting. During pregnancy, the upper GI tract may slow down and thus contribute to increased nausea and vomiting. Several studies have shown that this slowdown in the GI tract is increased in pregnant women with severe vomiting.
- Gastrointestinal: Helicobacter pylori bacteria that live in the intestinal tract may cause the development of peptic ulcer disease. These bacteria are found in a greater percentage among pregnant women and greater still in women with hyperemesis gravidarum. Antibiotics are used to treat all of these conditions.
- Psychosocial: Although the idea is controversial, some researchers think the condition may be a woman's psychological reaction against the pregnancy and might arise from conflict within the family and her home environment. In these cases, counseling is recommended.
Vomiting During Pregnancy Symptoms
Morning sickness: Some women experience nausea and vomiting only in the morning. The majority of women have nausea on and off, all day long.
- A pregnant woman may also note increased saliva, increased sensitivity to certain smells, and changes in the taste of some foods.
- Symptoms usually begin four to eight weeks after the woman's last menstrual period, peak at about
9-11 weeks, and go away by 14-16 weeks into the pregnancy.
- Fever, diarrhea, and severe abdominal pain are not associated with nausea and vomiting during pregnancy. If these symptoms occur, be sure to talk with your
doctor because it may be something other than morning sickness.
Hyperemesis gravidarum: This condition occurs when a pregnant woman has ongoing vomiting that results in weight loss greater than 5% of her body weight, and evidence of dehydration. Hyperemesis gravidarum is an extreme form of nausea and vomiting in pregnancy that sometimes requires hospitalization. It is different from, and much worse than morning sickness.
Am I Pregnant?
Early Pregnancy Symptoms
Women in the early stages of pregnancy may experience a number of different symptoms that may signal a pregnancy. While a missed menstrual period is often the characteristic sign of pregnancy, women who do not have regular menstrual cycles may not recognize that a menstrual period has been missed. In some cases, breast tenderness or other symptoms are the first sign of pregnancy. Still other women may not experience any particular symptoms at all during early pregnancy and may not be aware of their condition. The experience of pregnancy symptoms is highly individualized and differs among women. In fact, a woman may experience different symptoms in a second or subsequent pregnancy than she did in her first pregnancy.
When Should You See a Doctor for Vomiting During Pregnancy?
Call a doctor if self-care at home does not help reduce the symptoms, or if you are unable to take (and keep down) any liquids for more than 24 hours. Also call when you vomit on and off, but more than usual, or if the vomiting is associated with these symptoms, which may stem from other causes:
Go to a hospital's emergency department when you vomit continually and you have these symptoms of dehydration:
Vomiting During Pregnancy Diagnosis
Your doctor may ask for a urine sample to check for ketones, which is a chemical found in dehydration. In severe cases, your
doctor may also take blood samples to check your blood sugar,
electrolyte (sodium, potassium, chloride, and bicarbonate) levels,
liver function, or levels of certain hormones.
These tests may help your doctor determine your level of
They may also help decide if a different condition is causing your nausea and vomiting, such as a urinary tract infection, hepatitis, or gallstones.
Depending on how far along you are in your pregnancy, the doctor may also check the baby's health by listening for a heartbeat with a Doppler instrument, or by ultrasonography.
Your doctor may diagnose hyperemesis gravidarum only after excluding other serious illnesses. The following are other disorders that may show symptoms similar to hyperemesis gravidarum:
What Is the Treatment for Vomiting During Pregnancy?
If your symptoms are not severe and you have not already done so, your doctor may suggest you try home care treatments (please see Home Remedies). If you have tried these and are still vomiting, your doctor may suggest fluids be given to you with an IV. Often these fluids contain sugar as well as electrolytes. Many times fluid intake alone (IV or oral) can break the cycle of nausea and vomiting and temporarily make you feel much better.
Home Remedies for Morning Sickness (Vomiting During Pregnancy)
As miserable as it may seem, nausea and vomiting are usually part of a healthy pregnancy. The misery typically goes away by the middle of the second trimester. You can try home remedies to reduce your symptoms, and if these do not work, your doctor can help.
No single treatment works best for every woman with nausea and vomiting during pregnancy. Different techniques work for different women. You will have to discover what seems to make your symptoms better. Many women have found the following suggestions helpful:
- Eat small amounts of food frequently so that you are never too hungry or too full.
- Avoid spicy and fatty foods, and foods with odors that bother you.
- Try eating simple carbohydrates, such as saltine crackers, unbuttered toast, plain baked potatoes, white rice, gelatin desserts, broth, pretzels, popsicles, herbal or decaffeinated tea with sugar, or non-diet ginger ale.
- Combine these simple carbohydrates with a serving of protein, especially right before bed to minimize swings in blood sugar that may contribute to nausea.
- Drink liquids between meals and not during meals to minimize nausea and vomiting.
- Keep crackers at the bedside table to help with nausea in the morning.
- If you find that your prenatal vitamin seems to worsen your nausea, take it with food instead of on an empty stomach. If this does not help, talk to your doctor about the possibility of switching to a different vitamin. Chewable vitamins are sometimes easier to tolerate.
- Some evidence suggests that pyridoxine (vitamin B-6) supplements help reduce nausea and vomiting. The suggested dose is 25-50 mg every eight hours, and it can be given as an injection up to 200 mg. There are no known harmful effects of vitamin B-6 taken at these doses. Some prenatal vitamins are formulated with extra vitamin B-6.
- Stimulation of the P6 (Nei Guan) acupressure point on the wrist (on the inside of the wrist about where a watchband is worn) has been suggested as a method to reduce nausea and vomiting.
- You can press on this area with your finger or thumb or buy an acupressure band. These bands are often sold as motion sickness treatments, so check with a local drug store or auto club.
Glucose, fructose, and phosphoric acid
Glucose, fructose, and phosphoric acid are available over-the-counter. These solutions may reduce muscle contractions in the wall of the stomach and intestines. The normal dose is 1-2 tablespoons every 15 minutes for no more than 5 doses. These solutions cause no known harmful effects on the fetus.
Two over-the-counter antihistamines, diphenhydramine (Benadryl) and dimenhydrinate (Dramamine), have been shown to improve nausea and vomiting. Although both are generally believed to be safe in pregnancy, you should discuss the risks and benefits of these medications with your doctor.
- Powdered ginger is used fairly commonly in Europe as a nausea remedy during pregnancy.
- The usual dose is 250 mg, three times daily.
- The effect of ginger on the fetus has not been extensively studied.
What Is the Treatment for Morning Sickness (Vomiting During Pregnancy)?
- Your doctor will try to stop the vomiting either by hydration (giving fluids by IV or by mouth) or with medications.
- You will be given plenty of fluids to replace important electrolytes such as potassium.
- You also may receive thiamine (vitamin B-1) either as an injection or IV, depending how long you have been vomiting.
- Once these goals are met, you may be given antinausea medications and instructions for care at home.
- If you continue to be severely dehydrated, still nauseated, or still vomiting, you may be admitted to the hospital. Rarely, you may need to be hospitalized for fluid and nutritional supplements in very severe cases of hyperemesis gravidarum.
Medications for Morning Sickness (Vomiting During Pregnancy)
Your doctor may prescribe medications to reduce nausea and vomiting. Several effective prescription medications have been widely used in pregnancy with no evidence of harm to the fetus or the mother. Your doctor may prescribe one of these antiemetics (drugs that prevent or decrease nausea and vomiting).
How Do You Prevent Morning Sickness (Vomiting During Pregnancy)?
You may not be able to prevent nausea during the early part of your pregnancy, but you can minimize your symptoms. It can become a vicious cycle, where nausea leads to vomiting, which leads to dehydration, which leads to more nausea. The earlier you can control the symptoms, the better.
"Take home" suggestions to remember:
- Nausea and vomiting during pregnancy usually last several weeks.
- No one thing helps everyone.
- Get to know what techniques work best for you and use them.
Does Morning Sickness Mean There's a Problem With my Pregnancy?
Most women who experience nausea and vomiting during the early part of pregnancy go on to have healthy babies. In fact, some evidence indicates that women with mild-to-moderate nausea and vomiting are less likely to miscarry than are women who experience no symptoms at all. Some experts say that mild nausea and vomiting in pregnancy might have served some evolutionary advantage for early humans.
- Women with very severe symptoms, especially with dehydration and weight loss, are at higher risk for slowed fetal growth and low birth weight babies.
- Most women improve with IV fluids that may be given for several days without other measures.
- Women with continual vomiting and dehydration require IV fluid replacement in a medical setting off and on.
- Few women with hyperemesis gravidarum require a prolonged stay in the hospital, usually 7-10 days with continued treatment on an outpatient basis for 10-21 days.
- While in the hospital or as an outpatient, you may require a nasal feeding tube for placing fluid into your stomach or an IV to place fluid into a blood vessel.
Reviewed on 1/19/2018
Medically reviewed by Wayne S. Blocker, MD; Board Certification Obstetrics and Gynecology
"Patient information: Nausea and vomiting of pregnancy (Beyond the Basics)."