Severe vomiting in pregnancy | Mate ruaki i te hapūtanga

Also known as hyperemesis gravidarum

Key points about severe vomiting in pregnancy

  • Severe vomiting in pregnancy (mate ruaki i te hapūtanga) is known as hyperemesis gravidarum. It occurs in 1 to 2% or pregnancies.
  • If you are being sick often and can't keep food down, there's a risk you could become dehydrated, malnourished and lose weigfht. 
  • Tell your midwife or doctor. They will make sure you're getting the treatment you need.
  • While symptoms often improve around week 20, they may not clear up completely until your baby is born.
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Anyone who has had nausea and vomiting in pregnancy (often called morning sickness) will tell you it’s a miserable feeling. For some people, the symptoms are so severe or last so long that they’re unable to keep down enough food and fluids to nourish themselves. This is known as hyperemesis gravidarum. About 1 to 2 out of 100 pregnant people experience hyperemesis gravidarum. It's not known exactly what causes it, or why some people get it and others don't. However it’s thought to be due to high levels of hcg (human chorionic gonadotrophin), as symptoms are usually worst during the peak levels of hcg.

You are more likely to experience hyperemesis gravidarum if you:

  • are carrying twins or multiples (which causes higher levels of hcg)
  • have a mother or sister who has had hyperemesis gravidarum in a pregnancy
  • had hyperemesis gravidarum in a previous pregnancy.

Pregnancy nausea is usually limited to the first 3 months (or first trimester) of pregnancy. It eases off at about 12–14 weeks as the placenta becomes established and the pregnancy hormones such as hCG (human chorionic gonadotrophin) reduce. 

With hyperemesis, symptoms can start earlier, at about 6 weeks, and are much more severe than normal morning sickness. Some people report vomiting (being sick) up to 50 times a day. On average, symptoms of hyperemesis improve at about week 20 but they can be experienced until birth.

Often people who are pregnant can identify specific triggers for their nausea, eg, specific smells, feeling hot or certain foods.

About 10% of pregnant people will still have nausea and vomiting despite following preventative measures and recommendations. If you’re 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
  • light-headedness or fainting.

Signs of malnutrition include:

  • weight loss
  • light-headedness or fainting
  • feeling weak
  • appearing more pale than usual
  • feeling cold all the time
  • low mood
  • ketosis – a condition 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) which can be very serious in pregnancy.

If you have severe nausea and vomiting contact your midwife or doctor, ideally before you become dehydrated or start to lose weight. Your symptoms may improve with anti-nausea medicines and B6 vitamin supplementation, so it’s worth getting onto it early.

Contact your GP or midwife immediately if you:

  • have very dark-coloured urine or don’t 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 (throw up) blood
  • have pain when passing urine or any blood in your urine (this may be a urine infection).

As unpleasant as hyperemesis gravidarum is, the good news is it’s 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’s an increased risk your pēpi will be born smaller than expected (low birth weight).

If your nausea and vomiting is preventing you from carrying out your usual daily activities, see your midwife or healthcare provider 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’s no evidence to suggest that they’re harmful to your baby. Vitamin B6 (pyridoxine) may also be helpful. Always check with a doctor, midwife or pharmacist before taking any medicine or supplement when you're pregnant.

You may also have an ultrasound to see if you are having twins/multiple pregnancy and to make sure the pregnancy is normal.

If your nausea and vomiting can’t 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 your health of you and your baby.

In hospital, it’s likely:

  • you’ll be asked to provide a urine sample (to make sure there’s no infection and to check your ketone level), and a blood test will be done to check your electrolyte levels and your kidney/liver/thyroid function
  • you may be given IV fluids via a drip – this will be continued until you’re able to drink fluids without vomiting
  • you’ll be given anti-nausea medication and a B vitamin called thiamine, either via a drip or as tablets.

Very rarely, in severe cases, nutrients may be given via a nasogastric tube (tube that goes from your nostril to your stomach) or intravenously through a drip. 


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

Rest as much as possible and avoid getting overtired. You’re 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’re feeling better. Just do the essential things and ask for help with everything else.

Avoid nausea triggers

Many people find sensory stimulation, eg, 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. 

Stay hydrated

Ongoing vomiting can lead to dehydration, so you need to make sure you're 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 (eg, Popsicles or Frujus), 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 to 3 hours.
  • A bland, protein-rich diet may be more bearable.
  • 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 leads 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.
  • Gentle exercise in fresh air (eg, a walk outside) can make you feel better.
  • Make sure you’re getting enough sleep and have a nap during the day if you can.
  • If the smell of food is triggering for you, try eating cold food instead.

Foods that tend to be easier to tolerate 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 or flat lemonade
  • plain sweet biscuits
  • plain vegetables
  • peppermint, ginger or chamomile tea. 

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 (be sick)
  • 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’re feeling down or alone, 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, whānau and friends if you want to.

Hyperemesis gravidarum is much worse than regular pregnancy sickness. It’s not the result of anything you have or haven't done, and it’s important you get treatment and support.

Morning sickness – when to see a doctor(external link) NHS Choices, UK
Pregnancy – morning sickness(external link) Better Health Channel, Australia
Severe vomiting in pregnancy(external link) NHS Choices, UK 
What is hyperemesis gravidarum?(external link) Pregnancy Sickness Support, UK  


  1. Hyperemesis gravidarum RACGP, Australia, 2007
  2. Guideline to the management of nausea and vomiting in pregnancy and hyperemesis gravidarum Society of Obstetric Medicine of Australia and New Zealand, 2020
  3. Nausea and vomiting in pregnancy BPAC, NZ, 2011
  4. Hyperemesis gravidarum – assessment and management Australian Family Physician, 2017 

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Credits: Healthify editorial team. Healthify is brought to you by Health Navigator Charitable Trust.

Reviewed by: Dr Phoebe Hunt, Medical Officer, Northland

Last reviewed: