​Hyperemesis gravidarum is severe nausea and vomiting during pregnancy that lasts for more than a few days.

Last updated: 11 December 2023

​​​​​​​​​​​​​​​​​​​​​​​​​What is nausea and vomiting in pregnancy ​(NVP)?

Many pregnant women feel sick (nausea) and, or may vomit during early pregnancy. This can vary from mild to moderate and still be considered part of the normal experience of pregnancy. People used to call this “morning sickness” but we now refer to it as nausea and vomiting in pregnancy, or NVP.

In mild and moderate NVP women are still able to eat and drink. Around 7 in 10 pregnant women will experience NVP, but they usually feel better after the first trimester.

What is hyperemesis gravidarum (HG)?​​

When nausea and vomiting become severe, lasting for more than a few days, women will find it hard to eat or drink enough. This severe NVP is called hyperemesis gravidarum (HG). Around 1 in 100 pregnant women will experience HG, although this number may be higher. It may lead to dehydration (lack of fluid in the body) and cause weight loss and vitamin deficiencies.

HG usually starts early in pregnancy, before women are 16 weeks pregnant. For most women, HG stops between 13 to 20 weeks, while a few women have HG their entire pregnancy.

HG can have a big impact on women’s emotional, mental and physical health. Women are often so sick they cannot go to work, care for themselves or anyone else, and have great difficulty participating in normal daily activities.

HG can make women feel very unwell and needs to be taken seriously by their health care provider, families and support people and employers.

Where can I get help for my nausea and vomiting?


Help and support

If you are suffering from NVP or think you may have HG, you should see your pregnancy care provider, such as your midwife, family doctor or obstetrician. If you are feeling very unwell you should go to the Emergency Department at your local hospital for advice and help.

Symptoms of nausea and vomiting can become harder to control the longer you are suffering. We encourage you to see your pregnancy care provider as soon as possible when you feel that:

  • you are having difficulty eating or drinking because of the nausea and or vomiting
  • you are not able to cope alone at home.

Unfortunately, HG is often not always recognised quickly, so don’t be afraid to ask any questions about your health during pregnancy.


MotherSafe is a free telephone service for the women of NSW that can provide counselling and advice on medications to manage nausea and vomiting in pregnancy.

Call 1800 647 848 or search ‘MotherSafe NSW’ for more information.

Common to morning sickness
SymptomHyperemesis gravidarum (HG)
You may feel sick or vomit between 4 and 16 weeks of your pregnancy, but not usually to the extent that it disrupts your life. You can normally keep some food and water down over the course of the day.
You vomit a lot and find it hard to eat or drink anything, and to keep food down. For some women, it is a constant cycle of feeling unwell and being sick for weeks and even months. Vomiting can ease and then return during the pregnancy for some women.
You won’t normally lose much weight in pregnancy. It’s more common that you will gain rather than lose weight.
Weight loss
You may lose weight from being so unwell, and unable to keep enough food and/or fluids down.
Some tiredness is common in pregnancy, but it shouldn’t stop you from taking part in daily life, leaving the house or caring for your family.
You feel exhausted from constant sickness and are unable to do everyday tasks, go to work or care for others. Sleeping properly can be a problem. Sometimes you may struggle to look after yourself.
You won’t normally suffer from dehydration in most pregnancies. You can drink enough fluids to stay hydrated.
You may suffer dehydration from loss of fluids. You may need to go to hospital for treatment with medications and fluids.
It can be common to have moments of nausea in the first trimester, but it’s manageable and shouldn’t cause too much discomfort. Fluids and rest can help relieve the symptoms.
Nausea and/or vomiting severely impacts your daily life. Some women with HG find these symptoms stop after a few weeks, others may have these for their entire pregnancy.
It’s normal to feel some anxiety about the big changes pregnancy brings to your life. While you may feel a bit up and down, for the most part you should feel like your normal self and enjoy social activities and interests.
Anxiety, depression and isolation
Women who have HG, and have been unwell and tired for a while, can also feel very isolated, anxious and depressed. You may find it hard to cope and cannot enjoy your pregnancy. You may be afraid to plan future pregnancies due to the symptoms you have had.

How do I know if I have HG?

If you are experiencing nausea and or vomiting, which is interrupting your ability to drink and eat, you should speak to your health care provider. They may ask you questions about how you have been feeling over the past 24 hours. The “PUQE-24” scoring system below shows how they will rate your responses, to understand how severe your nausea and or vomiting has been.

If your PUQE-24 score is:

  • between 4 – 6, you have mild NVP
  • between 7 – 12, you have moderate NVP
  • ≥13, you have severe NVP (also known as HG).
​​​​​​​​PUQE-24 score
​​​​1. In the last 24 hours, for how long have you felt nauseated or sick to your stomach?
Not at all 
​1 hour or less 
​2-3 hours
​4-6 hours  
​More than 6 hours
​​​​2. In the last 24 hours, have you vomited or thrown-up?
​I did not vomit 
​​1-2 times
​​3-4 times  
​​5-6 times
​​7 or more times
​​​​3. the last 24 hours, how many times have you had retching or dry heaves without throwing up?
​​ (1)
​​​1-2 times
​​ (2)
​​​3-4 times
​​  (3)
​​​5-6 times
​​ (4)
​​​7 or more times
​​​ (5)

​​HG is a real and debilitating medical condition, and it is important that you are listened to and get the treatment you need.

Based on your responses to the questions, your health care provider will suggest how to manage your sickness. If you have mild or moderate feelings of nausea and vomiting you do not usually need any other tests, however you may be offered some treatment for your symptoms.

If you have severe NVP or HG, your pregnancy care provider should do further tests, such as blood or urine tests. These tests will look for the cause of your nausea and vomiting and see how dehydrated you are. The results of the tests will help guide your treatment.

What is causing my HG?

The first thing to know is that nothing you do or have done has caused HG. It’s not you or your partner’s fault and it does not mean there is anything wrong with your baby or your pregnancy. The exact cause of HG is not known but there are current studies on what the causes may be. So far we know that HG can occur more in some families. If you had severe sickness and vomiting in a previous pregnancy, you may be more likely to experience it again in later pregnancies. It seems to occur more when women have twins or triplets, however it definitely affects women who are pregnant with one baby too.

How is NVP and HG treated?

There is a lot of help available to ease your symptoms during pregnancy. Your pregnancy care provider will develop a treatment plan with you based on your symptoms and their severity. Sometimes the nausea and vomiting cannot be stopped completely. The aim of treatment is to reduce your symptoms enough to allow normal daily activities, especially eating and drinking.

If you have mild or moderate NVP, your health care provider may suggest:

  • changing your activities to get more rest
  • eating small amounts of food more often
  • sipping small amounts of fluid more often
  • ginger
  • avoiding vitamins which contain iron
  • anti-sickness (antiemetic) medication
  • pyridoxine (vitamin B6)
  • intravenous (IV) fluids* (fluids by a drip).

If you have severe NVP/HG, or you are dehydrated, your health care provider may suggest:

  • anti-sickness (antiemetic) medication
  • IV fluids*
  • other types of treatment and care, depending on your needs.

*Some women need to be seen at the hospital or Day Stay hospital facility (or hospital in the home) to be given IV fluids. You may need to be admitted (stay in) hospital if you do not respond to medication, you are losing weight or can’t keep enough fluid down and become dehydrated.

​Are medications safe to use in pregnancy?

Anti-sickness (antiemetic) medicine may be needed if your symptoms are not going away and are severe. You may be worried about taking medicines while you are pregnant. The medicines that health professionals recommend are considered safe and have been used for many years to treat nausea and vomiting in pregnancy. For some women, medication may be needed for several weeks or even months until symptoms settle.

Never take any medication without discussing it with your GP, obstetrician, community pharmacist or midwife. You can also call MotherSafe to get more information about medications.

Does HG and nausea and vomiting in pregnancy affect the baby?

Your baby gets its food from your body even though you may not be eating much when feeling nauseous or vomiting. If you become dehydrated it could affect your baby so it’s important you receive treatment and fluids. Some babies of women with HG may have a low birth weight when born. However, not all babies born to women with HG have a low birth weight.

Personal experiences with HG

Disclaimer: The following video shows women talking about their experience with HG, some viewers may find this upsetting.  For help with pregnancy sickness call MotherSafe on 1800 647 848.​

Current as at: Monday 11 December 2023
Contact page owner: NSW Health