Nausea in pregnancy: Causes, symptoms and treatment

Nausea is a common symptom during early pregnancy, affecting up to 70% of pregnant women. Though it's referred to as morning sickness, nausea can strike at any time during the day or night. Most of the time, nausea during pregnancy is harmless to unborn babies. Still, it can make you feel awful and negatively affect your quality of life. Learn how long this unpleasant symptom can last and how to make yourself more comfortable in the meantime.

The cause of nausea during pregnancy isn't fully understood. Some studies show that human chorionic gonadotropin (hCG), the pregnancy hormone, may be to blame. The body starts making hCG soon after the fertilized egg implants in the uterine lining, and levels quickly increase over the next several weeks before they plateau and eventually taper off. Estrogen levels also increase during early pregnancy, and may play a role in causing nausea. Slowed movement of foods through the digestive tract and genetic factors may also contribute to morning sickness symptoms.

Nausea is often one of the first signs of pregnancy. Most often, it starts before nine weeks. For most women, nausea subsides by the end of the first trimester. However, in some cases, it can last for several more weeks or months. Rarely, women experience nausea into late pregnancy that doesn't go away until the baby is born.

Specific morning sickness symptoms vary between women and between pregnancies. Some women may only feel sick after being triggered by a specific odor. Other women may be nauseated for a few hours each day and vomit from time to time. In severe cases, pregnant women experience constant nausea and regular vomiting.

Be sure to tell your healthcare provider if you have nausea during pregnancy. Even if your symptoms are mild, it's important for your provider to be aware so they can monitor you and suggest treatment, if needed. Contact your healthcare provider right away if you:

• Have severe nausea and vomiting
• Cannot keep down liquids
• Pass only a small amount of urine or have urine that looks darker than normal
• Feel dizzy or faint when you stand up
• Feel like your heart is racing

These can be signs of hyperemesis gravidarum, a rare but severe form of morning sickness. It can lead to problems, including weight loss and dehydration. Women with this condition need treatment to stop vomiting and replenish fluids.

Treatment for nausea often starts with dietary and lifestyle changes. Try these tips to help prevent and ease nausea:

• Stay away from nausea triggers. Common triggers include strong odors, stuffy rooms, heat and humidity, noise and motion.
• Avoid having an empty stomach, which can worsen nausea. Eat small servings of foods every hour or two throughout the day. If you don't feel well when you wake up, try having a small snack, such as crackers, before you get out of bed.
• Drink cold liquids between meals. Sip on clear fluids so your stomach doesn't become too full. Some women handle cold, clear, carbonated or sour beverages better than other drinks.
• Pass up foods that aggravate nausea. Common nausea culprits include fatty, acidic or spicy foods, coffee and foods with strong odors.
• Stick with foods you can tolerate. Salty, low-fat, protein-rich or bland foods may sit better in your stomach than other options. Many women also tolerate cold foods better than hot foods. Peppermint tea or peppermint candies may also temporarily relieve nausea.
• Try ginger. Ginger-containing foods and drinks, such as ginger gum or ginger tea, may improve nausea during pregnancy.

If home remedies don't bring you enough relief, talk to your healthcare provider. They may suggest taking pyridoxine (vitamin B6), doxylamine (Unisom) or both medicines together. These medications can relieve mild nausea during pregnancy. If your symptoms don't improve, your provider may recommend prescription anti-nausea medications.

Even though you may feel miserable, know that bouts of nausea during pregnancy are normal. In fact, it may even be a sign of a healthy pregnancy. Some research suggests that morning sickness may be a sign of a healthy placenta. However, you should not be concerned if you don't have nausea. Plenty of women have healthy pregnancies and never feel sick to their stomachs. Nausea tends to improve after the first trimester and can often be managed with home remedies. If you have severe nausea and vomiting or if lifestyle changes don't improve your symptoms, see your healthcare provider. They may recommend medications that are OK to take during pregnancy.

Clinically reviewed and updated April 2023.