When can nausea start in pregnancy

Symptoms of morning sickness

Symptoms of morning sickness can include:

• nausea
• loss of appetite
• vomiting
• psychological effects, such as depression and anxiety.

The myth of hysteria and morning sickness

Unrelenting morning sickness can have a profound effect on your quality of life, preventing you from working, socialising and looking after your other children.

Pregnant women enduring morning sickness report higher levels of psychological stress, including anxiety and depression. This prompted the false belief that morning sickness is purely psychosomatic, which means that the woman’s fears and anxieties trigger her physical discomfort. However, there is no research to support these claims.

Possible causes of morning sickness

The cause of morning sickness remains a mystery, but it is thought a combination of physical and metabolic factors play a significant role, including:

• high levels of hormones, including oestrogen
• fluctuations in blood pressure, particularly lowered blood pressure
• altered metabolism of carbohydrates
• the enormous physical and chemical changes that pregnancy triggers.

Morning sickness and your baby

Some women are concerned that the action of vomiting may threaten their unborn baby. Vomiting and retching may strain the abdominal muscles and cause localised aching and soreness, but the physical mechanics of vomiting won’t harm the baby. The fetus is perfectly cushioned inside its sac of amniotic fluid.

Numerous studies have discovered that moderate morning sickness is associated with a reduced risk of miscarriage. However, prolonged vomiting (that leads to dehydration and weight loss) can deprive your child of proper nutrition and increase the risk of your baby being underweight at birth.

If you have nausea and vomiting that will not stop, contact your GP (doctor) or midwife.

Severe morning sickness (hyperemesis gravidarum)

Severe morning sickness is known as hyperemesis gravidarum (HG), and can affect around one in 1000 pregnant women. The symptoms of HG include repeated vomiting, weight loss and dehydration. Treatment usually involves hospitalisation, and the administering of intravenous liquids and nutrition.

The possible complications of untreated hyperemesis gravidarum include:

• electrolyte imbalances
• extreme depression and anxiety
• malnourishment of the fetus
• excessive strain on vital organs, including the liver, heart, kidneys and brain.

Managing morning sickness

Suggestions for coping with morning sickness include:

• Don’t take drugs of any kind, unless your doctor knows you are pregnant and has prescribed specific medications.
• Eat a few dry crackers or plain sweet biscuits before getting out of bed in the morning.
• Don’t eat anything that you suspect will make you nauseous. In general high-carbohydrate meals are well tolerated.
• Eat small meals regularly, as an empty stomach tends to trigger nausea.
• It may help to avoid cooking or preparing foods.
• Drink as much as you can manage. Sometimes sips of flat lemonade, diluted fruit juice, cordial, weak tea, ginger tea, clear soup or beef extract drinks are helpful. If none of these are bearable, try sucking on ice cubes.
• Vitamin B6 supplements can be useful, but doses above 200 mg per day can actually be harmful. Follow your doctor’s advice.
• Consider acupressure or acupuncture on the wrist.
• Wear loose clothes that don’t constrict your abdomen.
• Moving around may aggravate morning sickness. Rest whenever possible.

Seeing your doctor about morning sickness

Always seek medical advice if your morning sickness is severe, if you have lost a lot of weight quickly, or if you feel depressed or anxious. Treatment options can include medication that won’t harm your developing baby.

Where to get help

• Nausea and vomiting in pregnancy , The Royal Women’s Hospital.
• Chan RL, Olshan AF, Savitz DA, et al., 2010, ‘Severity and duration of nausea and vomiting symptoms in pregnancy and spontaneous abortion ’, Human Reproduction, vol. 25, no. 11, pp. 2907–2912.

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This page has been produced in consultation with and approved by:

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Morning sickness (also called nausea and vomiting of pregnancy) is nausea (feeling sick to your stomach) and vomiting that happens in the first few months of pregnancy. Even though it's called morning sickness, it can last all day and happen any time of day.

At least 7 in 10 pregnant women have morning sickness in the first trimester (first 3 months) of pregnancy. It usually starts at about 6 weeks of pregnancy and is at its worst at about 9 weeks. Most women feel better in their second trimester, but some have morning sickness throughout pregnancy. If you have morning sickness, tell your health care provider.

Mild morning sickness doesn’t harm you or your baby. But if nausea and vomiting becomes severe (called hyperemesis gravidarum), it can cause serious problems during pregnancy. You may need to stay in the hospital for treatment. 

What is hyperemesis gravidarum?

About 3 in 100 women may have hyperemesis gravidarum. This is extreme, excessive nausea and vomiting during pregnancy. It can cause you to lose weight and become dehydrated (not have enough water in your body). It can start early in pregnancy and last the entire pregnancy. If you have hyperemesis gravidarum, you need treatment to help keep you and your baby safe.

You may be at risk for hyperemesis gravidarum if you:

• Are pregnant for the first time.
• Are pregnant with a girl.
• Are pregnant with multiples (twins, triplets or more). Being pregnant with more than one baby may increase your risk for severe morning sickness because you may have a large placenta and increased pregnancy hormones. The placenta grows in your uterus (womb) and supplies your babies with food and oxygen through the umbilical cord.   
• Had mild or severe morning sickness in a previous pregnancy, or your mother or sister had severe morning sickness during pregnancy. Take your family health history to help you find out about health conditions that run in your family. 
• Have motion sickness or migraines.  A migraine is a severe headache that may make you sensitive to bright lights and sound.
• Are overweight.
• Have trophoblastic disease, a condition that leads to abnormal cell growth in the uterus (womb).

Signs and symptoms of hyperemesis gravidarum include:

• Vomiting more than 3 to 4 times a day 
• Vomiting that makes you dizzy or lightheaded
• Vomiting that makes you dehydrated. Signs and symptoms of dehydration include feeling thirsty, dry mouth, a fast heartbeat or making little to no urine. 
• Losing more than 10 pounds in pregnancy 

If you have hyperemesis gravidarum, your provider may treat you with medicine to help relieve your nausea and vomiting. You may need treatment in a hospital with intravenous (also called IV) fluids. IV fluids go through a needle into your vein. They help you stay hydrated and can give you nutrients that you usually get from food.  If you continue to lose weight, you may need a feeding tube to make sure you’re getting enough nutrients for you and your baby. 

What causes morning sickness? 

We don’t know for sure what causes morning sickness. It may be caused by low blood sugar or increased pregnancy hormones. Morning sickness may be worse if you’re stressed or overly tired, if you eat certain foods or if you’re traveling (if you often have motion sickness).

Can you prevent or relieve morning sickness?

Yes. Here’s what you can do to help you feel better and even prevent morning sickness:

• Take a prenatal vitamin before you get pregnant. Talk to your health care provider about which one to take. Sometimes vitamins can upset your stomach, so take it with a snack.
• Keep snacks by your bed. Eat a few crackers before you get up in the morning to help settle your stomach.
• Eat 5 or 6 small meals each day instead of 3 larger meals.  
• Eat foods that are low in fat and easy to digest, like cereal, rice and bananas. Don’t eat spicy or fatty foods. 
• Eat healthy snacks between meals. This can help keep your stomach from being empty and helps prevent nausea. Try snacks that are high in protein, like milk or yogurt. 
• Drink plenty of fluids, especially water.  
• Avoid smells that upset your stomach.

You may have heard about these ways to prevent or relieve morning sickness. Talk to your provider before trying any of these:

• Acupressure and acustimulation (also called electrical nerve stimulation) wristbands. These involve putting pressure on or stimulating certain points of the body (called pressure points) to help prevent nausea.  
• Acupuncture. This is a kind of treatment in which thin needles are put into your skin. If you’re thinking about acupuncture to help with morning sickness, tell your provider and find an acupuncturist who is trained to work with pregnant women.
• Ginger. Ginger is the root of a plant that is used in cooking and medicine. Ginger ale, tea or candies may help relieve morning sickness.

Even if it’s legal where you live for either personal or medical use, it’s not safe to use marijuana to treat morning sickness. No amount of marijuana has been proven safe to use during pregnancy. If you’re thinking of using marijuana to help with morning sickness, talk with your provider about other treatments that are safer for your baby.

Is there medical treatment for morning sickness?

Yes. If you can’t relieve morning sickness on your own or if you have severe nausea and vomiting of pregnancy, your provider may treat you with these medicines:

• Vitamin B6 and doxylamine. Your provider may treat you with these medicines separately or together. You can get vitamin B6 and doxylamine over-the-counter (OTC), which means you don’t need a prescription for them from your provider. Doxylamine is found in some OTC medicines that help you sleep. Or your provider may prescribe you a medicine that combines them.
• Antiemetic drugs. These are drugs that help prevent vomiting. If Vitamin B6 and doxylamine don’t work, your provider may prescribe an antiemetic drug for you. Not all are safe to use during pregnancy, so talk to your provider to make sure the medicine is a good choice for you.

Talk with your provider before you take any medicine during pregnancy, even medicine to help treat morning sickness.

When should you call your health care provider about morning sickness?

For most women, morning sickness is mild and goes away over time. But call your provider if:

• Your morning sickness continues into your 4th month of pregnancy. 
• You lose more than 2 pounds. 
• Your vomit is brown in color or has blood in it. If so, call your provider right away.
• You vomit more than 3 times a day and can’t keep food or fluids down. 
• Your heart beats faster than usual. 
• You’re tired or confused. 
• You’re making much less urine than usual or no urine at all. 

Last reviewed: September, 2020