Vomiting in the Third Trimester: Causes and Potential Solutions

Updated November 14, 2022
Pregnant woman in the bathroom

After dealing with morning sickness in early pregnancy, some expectant parents are surprised to experience nausea and vomiting again in the third trimester. As your baby continues to grow and develop between weeks 27 to 40, you may experience a number of uncomfortable symptoms. Rest assured that in many cases, there is no reason to be concerned.

Nearly 33% of pregnant people experience nausea, and almost 24% experience vomiting in the third trimester. If you find yourself with these symptoms, it can be helpful to learn about potential causes and workable solutions. It is also important to know which symptoms should warrant a call to your healthcare provider.

Common Causes of Vomiting in Third Trimester

For some pregnant people, throwing up in the third trimester is simply an extension of the "morning sickness" they had in the earlier weeks of pregnancy. Known as hyperemesis gravidarum (HG), this condition causes persistent and severe morning sickness that often requires medication to manage. If you've been diagnosed with HG, you'll work with your healthcare team to manage your health during pregnancy.

If HG isn't to blame, one of the following may be the reason why you are throwing up in the third trimester:

Growing Baby and Abdominal Pressure

Your baby spends most of the third trimester growing and putting on layers of fat before they are born. As your baby grows, your pregnant belly grows along with it. Your growing uterus puts a lot of pressure on your stomach, and many pregnant people find it difficult to consume and digest large meals. If you do eat a big meal, you may feel nauseous. Try to eat smaller meals throughout the day to prevent nausea and vomiting.


Heartburn (acid reflux) is one of the most common causes of nausea in the third trimester. During pregnancy, the muscles of the valve between the stomach and esophagus relax due to the hormonal changes that occur during pregnancy. The relaxed muscles can cause stomach acid to move up into the esophagus, leading to heartburn.

Pressure on your stomach can also lead to heartburn in the third trimester. As your baby and uterus continue to grow, a lot of pressure is placed on your stomach, which can force acid upwards and lead to heartburn, nausea, and vomiting in the third trimester. If you're experiencing heartburn, eating smaller meals and/or taking antacids recommended by your healthcare provider may alleviate symptoms.


In some cases, nausea and vomiting may occur during labor. Most often, this will occur when you are close to your due date and will be accompanied by other labor symptoms, such as pelvic pressure, backache, and contractions. If you have nausea, vomiting, diarrhea, and/or abdominal cramping in your third trimester or at any time during your pregnancy, contact your healthcare provider. This could be a sign that you will be delivering your baby soon.

Stomach Virus or Food Poisoning

Food poisoning often results in nausea and vomiting, whether you are pregnant or not. But changes to your immune system during pregnancy can make you (and your unborn baby) more vulnerable to food-borne illnesses. These illnesses can cause severe symptoms during pregnancy and can lead to premature delivery.

Some food-borne illnesses can affect your unborn baby, such as listeria, according to the U.S. Department of Health and Human Services. Contact your healthcare provider right away if you suspect you have a case of food poisoning in your third trimester.

If food poisoning is not the cause of your nausea and vomiting, you may have a stomach virus. If you are experiencing severe nausea and/or diarrhea, dehydration becomes a concern. Symptoms of dehydration include:

Contact your healthcare provider if you suspect you have a stomach virus and are experiencing dehydration. They may recommend that you to go to the hospital for monitoring and IV fluids.

More Serious Causes of Third Trimester Vomiting

Sometimes, nausea and vomiting in the third trimester can be a sign of a more serious condition that requires medical attention. If any of these symptoms sound familiar, be sure to check with your healthcare provider to get personalized guidance.

Preterm Labor

While vomiting is sometimes a symptom of labor at full term (37 weeks or more), it may also be a sign of preterm labor. You may be experiencing preterm labor if you are less than 37 weeks pregnant and experience labor symptoms, such as:

  • Consistent contractions
  • Decrease in movements from baby
  • Leaking of fluid (amniotic sac)
  • Nausea
  • Pelvic pressure
  • Vomiting

In some cases, your healthcare provider may be able to delay delivery by prescribing medications to relax your uterus or putting you on bed rest to prevent further progression of labor. Depending on the health of you and your baby, you may still deliver your baby early.


Preeclampsia is characterized by high blood pressure during pregnancy. This condition is serious and potentially life-threatening, so it is important to know the signs and symptoms of preeclampsia, such as:

  • Changes in vision (e.g., blurred vision, light sensitivity)
  • Nausea or vomiting
  • Pain in the upper abdomen, usually under the ribs on the right side of the body
  • Protein in the urine
  • Severe headaches
  • Shortness of breath due to fluid in the lungs

Contact your healthcare provider immediately if you experience symptoms of preeclampsia. If left untreated, preeclampsia may cause seizure, coma, or death. If preeclampsia is diagnosed before the 36th week of pregnancy, you may be admitted to the hospital and placed on bedrest so you and your baby can be closely monitored. Medications may be prescribed to manage symptoms of preeclampsia, but the delivery of your baby is the only "cure."

HELLP Syndrome

HELLP (hemolysis, elevated liver enzymes, and low platelets) syndrome is a life-threatening complication that may occur during pregnancy. Considered a variation of preeclampsia, HELLP syndrome is rare and occurs in less than 1% of pregnancies. According to the Preeclampsia Foundation, symptoms of HELLP syndrome include:

  • Abdominal and/or chest pain and tenderness
  • Nausea, vomiting, or indigestion after eating
  • Pain when breathing
  • Persistent headache
  • Shoulder pain
  • Shortness of breath
  • Swelling in the hands and face
  • Vision changes (e.g., blurred vision, double vision, seeing auras or flashing lights)

Contact your healthcare provider immediately if you have one or more symptoms of HELLP syndrome. Your provider may give medications to reduce symptoms, such as blood pressure medication and steroids, to help your baby's lungs mature quickly. You may be admitted to the hospital and placed on bed rest for continued monitoring of your and your baby's health. If your symptoms are severe, you may need to deliver your baby early.

Should You Worry If You Throw Up in Late Pregnancy?

In many cases, nausea and vomiting in the third trimester are relatively minor and go away quickly. However, if your vomiting is persistent and/or accompanies other symptoms, contact your healthcare provider. They will want to see you for a check-up and evaluate your health so any potentially serious health issues can be addressed right away.

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Vomiting in the Third Trimester: Causes and Potential Solutions