This sheet is about having nausea and vomiting during pregnancy. This information is based on available published literature. It should not take the place of medical care and advice from your healthcare provider.

What is nausea and vomiting in pregnancy (NVP)?

NVP or “morning sickness” is the most common medical condition in pregnancy. About 80% of people who are pregnant can have NVP symptoms ranging from mild to severe. Symptoms might happen at any time during the day or at night. Symptoms can include nausea, dry heaves, retching, and/or vomiting. NVP usually begins between 4-9 weeks of pregnancy, and peaks between 7-12 weeks. In most people who are pregnant, symptoms go away between 12-16 weeks of pregnancy. Up to 15% of people who are pregnant will continue to have symptoms up to 20 weeks of pregnancy or until delivery.

The most severe form of NVP is known as hyperemesis gravidarum (HG) and happens in up to 3% of people who are pregnant. In HG there is severe nausea and constant vomiting that causes weight loss and dehydration (not getting enough water). People who are pregnant with HG can require hospitalization. Whether symptoms of NVP are mild, moderate, or severe, it can have a major impact on quality of life. If NVP is affecting your ability to eat/drink, sleep, and/or perform your daily activities, speak with your healthcare provider.

Taking prenatal vitamins might worsen NVP, as the iron might cause greater symptoms, upset stomach and/or cause constipation. Discuss this with your healthcare provider if you are having trouble taking your prenatal vitamin.

If symptoms of NVP first start at the 10th week of pregnancy or later, they might be due to other causes and should be discussed with your healthcare provider. See the paragraph below on “Could NVP be due to something other than pregnancy?”.

Does having NVP increase the chance for miscarriage?

Miscarriage is common and can occur in any pregnancy for many different reasons. Some studies have suggested that people who are pregnant with NVP might be less likely to have a miscarriage.

Does having NVP increase the chance of birth defects?

Every pregnancy starts out with a 3-5% chance of having a birth defect. This is called the background risk. Most studies have not shown an increased chance of birth defects above the background risk when a person who is pregnant has NVP.

Would having NVP increase the chance of other pregnancy related problems?

People who are pregnant with severe NVP or those who have HG are at a greater risk of malnutrition or getting dehydrated, as they might not be able to keep enough food or water down. This can cause medical complications for the person who is pregnant. Some studies have found that HG might be associated with a slightly higher chance of having a baby that is smaller than expected.

Does having NVP affect future behavior or learning for the child?

Severe NVP in pregnancy, with weight loss and long duration, might be associated with behavioral or developmental difficulties. Long-term outcomes are difficult to study and difficult to connect to a single cause. More data is needed to understand if these outcomes are due to the nausea and vomiting itself, the malnutrition that can happen with severe vomiting, the stress of dealing with prolonged NVP, or some other factor(s). If you have severe NVP be sure to check in with your healthcare provider about treatment options to help lessen symptoms.

Are there treatments for NVP?

It is helpful to treat NVP symptoms as soon as they start, as it might be easier to get them under control when treated right away. There are food and lifestyle changes that might help lessen NVP symptoms. There are also medications that have been used to treat NVP. Some pregnant people might need to use a combination of lifestyle changes and medications to help lessen their symptoms.

Changes in food and lifestyle that have helped some people to lessen NVP symptoms include:

• Eating small meals or a snack every 1-2 hours
• Adding a protein source to each snack and each meal
• Drinking cold or partially frozen fluids daily (8 cups)
• Keeping solids and liquids separate, by drinking 20 to 30 minutes before or after meals/snacks
• Eating bland foods that are gentle on the stomach, such as the BRAT diet (bananas, rice, applesauce, toast)

There are prescription medications that have been used to treat NVP. For information on specific medications in pregnancy, see our MotherToBaby fact sheets at https://mothertobaby.org/fact-sheets-parent/ or contact a MotherToBaby specialist. You and your healthcare provider should work together to find the best treatment options for your symptoms.

Could NVP be due to something other than pregnancy?

Discuss your specific NVP symptoms with your healthcare providers, as there are other medical conditions that could cause nausea and vomiting. For example, symptoms of heartburn, indigestion and/or acid reflux (such as burning, burping, belching, or nausea at night) affect 40-85% of people who are pregnant, and over 50% of symptoms will appear during the first trimester. Some people find heartburn relief when avoiding fatty/acidic foods, and when elevating the head of the bed to sleep on an incline (raising the head higher than the abdomen).

Another example, a bacterial infection called Helicobacter pylori, has been associated with HG. Testing for this bacterium has been recommended for people who are pregnant with a history of severe NVP or HG. If a pregnant person is positive for this bacterium, they can be treated during the pregnancy. Your healthcare provider can help to determine if there are other possible medical causes for your NVP symptoms.

In addition, the following website might be helpful: https://www.hyperemesis.org/.

Selected References:

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