Severe vomiting in pregnancy | Mate ruaki i te hapūtanga

Hyperemesis gravidarum

Severe vomiting in pregnancy (mate ruaki i te hapūtanga) is known as hyperemesis gravidarum. It is much worse than regular pregnancy sickness. If you are being sick often and can't keep food down, there is a risk you could become dehydrated. Tell your midwife or doctor. They will make sure you are getting the treatment you need.

On this page, you can find the following information:

 Key points

  1. Nausea and vomiting in pregnancy are common. It affects around 7 out of 10 women and, for most women, improves or disappears completely by around the end of the first trimester.
  2. Some women experience excessive nausea and vomiting. They may be sick many times a day and unable to keep fluids and food down. This is known as hyperemesis gravidarum.
  3. Hyperemesis is thought to affect around 1 out of 100 pregnant women. While symptoms often improve around week 20, they may not clear up completely until the baby is born.
  4. Hyperemesis is much worse than regular morning sickness and, without the right treatment and support, you may be at risk of becoming dehydrated and under-nourished.
  5. Talk to your midwife or doctor if you are vomiting and can’t keep any food or drink down. There are things that can be done to control nausea and vomiting to ensure you are getting enough fluid and nutrition.

What is hyperemesis gravidarum?

Any woman who has had nausea and vomiting in pregnancy (often called morning sickness) will tell you it is a miserable feeling. For some women, the symptoms are so severe or last so long that they are unable to keep down enough food and fluids to nourish themselves. This is known as hyperemesis gravidarum.

Around 1 out of 100 women experience hyperemesis gravidarum. It's not known what causes it, or why some women get it and others don't. You are more likely to experience hyperemesis gravidarum if you:

  • are carrying twins or multiples
  • have a mother or sister who has had hyperemesis gravidarum in a pregnancy
  • had hyperemesis gravidarum in a previous pregnancy.

What are the symptoms of hyperemesis gravidarum?

For most women, pregnancy nausea is limited to the first three months (or first trimester) of pregnancy. It eases off at around 12–14 weeks as the placenta becomes established and the pregnancy hormones such as hCG (human chorionic gonadotrophin) level off. 

With hyperemesis, symptoms can start earlier, around 6 weeks, and are much more severe than normal morning sickness. Some women report being sick up to 50 times a day. On average, symptoms of hyperemesis improve around week 20 but can last until birth.

When to seek medical attention

If you are unable to keep fluids and food down, you are at risk of dehydration (lack of fluids) and malnutrition (lack of nutrition).

Signs of dehydration include:

  • feeling ‘dry’ or very thirsty
  • urine changing from a light yellow to a dark yellow or brown colour.

Signs of malnutrition include:

  • weight loss
  • lightheadedness or fainting
  • ketosis – a serious condition that is caused by a raised number of ketones in your blood and urine (ketones are poisonous acidic chemicals that are produced when your body breaks down fat, rather than glucose, for energy).

If you have severe nausea and vomiting contact your midwife or doctor, ideally before you become dehydrated or start to lose weight.

Contact your GP or midwife immediately if you:

  • have very dark-coloured urine or do not pass urine for more than 8 hours
  • are unable to keep food or fluids down for 24 hours
  • feel severely weak, dizzy or faint when standing up
  • have abdominal (tummy) pain
  • have a high temperature (fever) of 38°C or above
  • vomit blood
  • have pain when passing urine or any blood in your urine (this may be a urine infection).

Will hyperemesis gravidarum harm my baby?

Unpleasant as hyperemesis gravidarum is, the good news is it is unlikely to harm your baby if treated effectively.

Most babies whose mothers have hyperemesis are fine with no serious after-effects. However, if hyperemesis causes you to lose weight during pregnancy there is an increased risk your baby will be born smaller than expected (low birth weight).

What is the treatment for hyperemesis gravidarum?

If your nausea and vomiting is preventing you from carrying out your usual daily activities, see your midwife or GP for an assessment.

There are a variety of anti-sickness medicines that you may be offered such as cyclizine, prochlorperazine, metoclopramide, ondansetron and steroids. Not all of these medicines are licensed for use in pregnancy, but there is no evidence that they are harmful to your baby. Always check with a doctor, midwife or pharmacist before taking any medicine or supplement when you are pregnant.

You may also have an ultrasound to check everything is okay.

If your nausea and vomiting cannot be controlled, you may need to be admitted to hospital. This is so doctors can assess your condition and give you the right treatment to protect the health of you and your baby.

In hospital you may be given:

  • fluids via a drip – this will be continued until you are able to drink fluids without vomiting
  • anti-nausea medication and a B vitamin called thiamine via a drip.

Very rarely in severe cases, nutrients may be given via a nasogastric tube or intravenously. 

Self-care for hyperemesis gravidarum


Severe sickness can be exhausting and stop you doing everyday tasks, such as going to work or even getting out of bed.

Rest as much as possible and avoid getting overtired. You are likely to have times when you feel worse and other times when you feel better. Avoid the temptation to try and catch up on tasks when you are feeling better. Just do essential tasks and ask for help with everything else.

Avoid nausea triggers

Many women find sensory stimulation such as noises, moving visual images, bright light, strong smells and even the movement of air from an open window can all trigger vomiting.

  • Avoid foods and food smells that make you feel nauseous.
  • Try sea-sickness acupressure bracelets or acupuncture.

Keep hydrated

Ongoing vomiting can lead to dehydration, so you need to make sure you are getting enough fluids.

  • Take small sips of water or other fluids regularly, rather than a glass at a time.
  • Try electrolyte drinks to keep up the levels of minerals and salts that you need.
  • If you can't tolerate drinks, try sucking ice cubes, iceblocks such as Popsicles or Fruju, or sipping very slowly through a straw.

Dietary tips

Hunger can make the nausea and vomiting worse.

  • Eat slowly and regularly. Have a small meal/snack every 2–3 hours.
  • A bland, protein-rich diet may be tolerable.
  • Carbohydrates are also important as our bodies use them for energy. If too little carbohydrate is eaten your body breaks down its own muscle stores, which lead to the production of ketones. Ketones in the blood cause an increase in nausea, so stopping this cycle is important.
  • Try eating a biscuit or crackers before you get out of bed.
  • Try to avoid coffee, spicy, smelly, high fat, fried, acidic and very sweet foods.

Foods that tend to be more tolerable include:

  • mashed potatoes
  • dry salty crackers
  • boiled sweets or barley sugars
  • potato chips
  • rice crackers
  • plain scones/muffins
  • tinned or fresh fruit
  • dry toast
  • jelly
  • diluted fruit juice
  • plain sweet biscuits
  • plain vegetables.

Coping emotionally

Hyperemesis gravidarum can have a huge impact on your life at a time when you were expecting to be enjoying pregnancy and looking forward to the birth of your baby.

As well as feeling sick, you might also feel:

  • anxious about going out in case you need to vomit
  • isolated because you don't know anyone who understands what it's like to have hyperemesis
  • unsure whether you can cope with the rest of the pregnancy if you continue to feel very ill.

If you feel any of these, don't keep it to yourself. Talk to your midwife or doctor, and explain the impact hyperemesis is having on your life and how it's making you feel. You could also talk to your partner, family and friends if you want to.

Hyperemesis gravidarum is much worse than regular pregnancy sickness. It is not the result of anything you have or haven't done, and you do need treatment and support.

Learn more

Nausea and vomiting in pregnancy BPAC, NZ, 2011
Morning sickness – when to see a doctor NHS Choices, UK
Pregnancy – morning sickness Better Health Channel, Australia
Severe vomiting in pregnancy NHS Choices, UK 
What is hyperemesis gravidarum? Pregnancy Sickness Support, UK  

Credits: Health Navigator NZ. Reviewed By: Lee-Ora Lusis, Clinical Nurse Director, Totara Health Last reviewed: 07 Mar 2019