Nausea and vomiting in pregnancy and hyperemesis gravidarum

Information for patients.

Obstetrics and gynaecology

What is nausea and vomiting in pregnancy (NVP)?

Nausea and vomiting in pregnancy (sometimes called morning sickness) is common. Around 8 out of every 10 pregnant women and birthing people feel sick (nausea), are sick (vomiting) or both during pregnancy. This does not just happen in the morning.

It is most common between weeks 4 and 7. For most people, this improves or stops completely by around weeks 12 to 20, although sometimes it can last longer.

What is hyperemesis gravidarum?

Some people experience very bad nausea and vomiting in pregnancy. They might be sick many times a day and be unable to keep food or drink down, which can impact on their daily life.

This excessive nausea and vomiting is known as hyperemesis gravidarum (HG), and often needs hospital treatment. HG affects 1 to 3 in every 100 pregnancies.

If you are being sick frequently and cannot keep food down, tell your Midwife or Doctor, or contact the hospital as soon as possible. There is a risk you may become dehydrated, and you may need treatment in hospital.

Signs and symptoms of HG include:

  • Prolonged and severe nausea and vomiting
  • dehydration - symptoms include feeling thirsty, tired, dizzy or lightheaded, not peeing very much, and having dark yellow and strong-smelling pee
  • weight loss

Unlike regular pregnancy sickness, HG may not get better by 16 to 20 weeks. It may not clear up completely until the baby is born, although some symptoms may improve at around 20 weeks.

See your GP or Midwife if you have severe nausea and vomiting. Getting help early can help you avoid dehydration and weight loss.

There are other conditions that can cause nausea and vomiting, and these will need to be ruled out first.

What is the cause?

It is not known exactly what causes it, but it could be from hormones produced in pregnancy. It is not clear why some people have a worse experience of this than others.

It is common in people who:

  • have had it before
  • are pregnant with twins or triplets
  • have a molar pregnancy (a very rare condition which affects less than 1 in 10,000 people). This condition causes an overgrowth of abnormal placental cells so baby does not form correctly. If you have already had an ultrasound, this may have already been ruled out.

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

Will it harm my baby?

It can make you feel very unwell but there is no evidence that nausea and vomiting has a harmful effect on your baby. There is a slightly increased risk of your baby being born with a low birth weight (smaller) if you lose weight during pregnancy.

How might it feel?

Nausea and vomiting in pregnancy can be a difficult problem to cope with. It can affect your mood, your work, your home life and your ability to carry
out usual daily activities.

In addition to feeling very unwell and tired, you might also feel:

  • anxious about going out or being too far from home in case you need to vomit
  • isolated because you do not know anyone who understands what it’s like to have HG
  • confused as to why this is happening to you
  • unsure about how to cope with the rest of the pregnancy if you continue to feel very ill

Support from family and friends can help. The symptoms can be so bad that it can affect your mental health and you may need extra support such as counselling. If you feel you need extra support please speak to a member of your healthcare team.

If you want to talk to someone who has been through HG, you can contact Pregnancy Sickness Support’s help section. They have a support network across the UK and can put you in touch with someone who has had HG.

When should I seek help?

Seek medical help from your GP or Midwife if you:

  • Are finding it difficult to eat and/or drink
  • Are frequently vomiting after eating or drinking
  • Have dark yellow or brown urine

You should seek urgent medical help if you:

  • Are unable to keep food or fluids down for 24 hours
  • Have lost weight
  • Are feeling dizzy or fainting
  • Are not passing urine

 With these symptoms it is important to seek help early to avoid damage to your organs.

What are my treatment options?

We try to treat vomiting in pregnancy in your home, as recovery is often better in your own home environment. This can include:

  • Antisickness medicines:

This will be in the form of tablets.

  • Acupin® therapy:

A form of acupuncture which works by inserting a small pin, which looks like a tiny, almost invisible plaster, into your wrist and is changed every 3 days. A member of the team will show you how to change this. It is a simple procedure but can be very good at reducing sickness.

If you do not get better with treatment at home, we would recommend you are treated in hospital. You will be seen by a Nurse and a Doctor who will ask you some questions and do the following:

  • Record your weight
  • Test your urine
  • Perform blood tests
  • Arrange an ultrasound scan for you (if not completed or arranged already)

Your healthcare team will use the results of these tests to help you choose the best treatment option for you.

If you need treatment in hospital this will be done in one day (hyperemesis ambulatory care). Your stay will only be about 4 to 6 hours. You will be offered fluids through a drip in your arm over a short period of time. This is called rapid rehydration.

You will also be given anti-sickness medication. You may feel much better after this and can then go home with anti-sickness medications. You can return if you start to feel poorly again.

If you have very severe symptoms such as excessive weight loss, muscle wasting, dehydration, dizziness or palpitations, abnormal test results, or if outpatient treatment did not work for you, admission to hospital will be necessary.

You will be offered or given:

  • the fluids you need though a drip in your arm. This will be continued until you are able to drink fluids without vomiting.
  • anti-sickness medication.
  • blood thinning injections and blood clot prevention stockings to reduce the risk of developing clots in either your legs or lungs.

Blood clots and hyperemesis gravidarum

Because HG can cause dehydration, there is also an increased risk of having deep vein thrombosis (a blood clot), although this is rare.

If you are dehydrated and immobile, there is treatment that you can be given to prevent blood clots.

What can I do to help myself?

Keep a diary of what brings on sickness (triggers) and nausea free times; avoid things such as strong smells that may trigger symptoms

  • Eat when you are hungry; small and frequent meals. Carbohydrates such as rice, pasta, dry toast and biscuits are usually better tolerated than spicy or greasy foods
  • Keep drinking small amounts regularly to avoid dehydration. Use ice cubes, frozen fluids or ice lollies
  • Some people find eating or drinking ginger products helps with nausea
  • Accept help and support from family and friends and carry on socialising when you can
  • Make sure you rest enough, but also keep moving when you can
  • Avoid strong smells that trigger symptoms
  • Wear comfortable clothing; avoid tight waistbands

How to contact us

Early Pregnancy Assessment Unit (EPAU)

01709 427072

Ward B11 (Gynaecology)

01709 424349

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  • Page last reviewed: 20 January 2023
  • Next review due: 20 January 2024