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Severe vomiting in pregnancy - Your pregnancy and baby guide

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

For most women, this improves or stops completely by around weeks 16 to 20, although for some women it can last longer.

Some pregnant women experience very bad nausea and vomiting. 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.

Exactly how many pregnant women get HG is not known as some cases may go unreported, but it's thought to be around 1 to 3 in every 100.

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 your midwife or doctor can make sure you get the right treatment.

Symptoms of hyperemesis gravidarum

HG is much worse than the normal nausea and vomiting of pregnancy.

Signs and symptoms of HG include:

  • prolonged and severe nausea and vomiting
  • being dehydrated. Symptoms of dehydration include, feeling thirsty, tired, dizzy or lightheaded, not peeing very much, and having dark yellow and strong-smelling pee
  • weight loss
  • low blood pressure (hypotension) when standing

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 your doctor will need to rule these out first.

See the healthtalk.org website for videos and written interviews of women talking about their experiences of hyperemesis gravidarum and how they coped.

What causes hyperemesis gravidarum?

It's not known what causes HG, or why some women get it and others do not. Some experts believe it is linked to the changing hormones in your body that occur during pregnancy.

There is some evidence that it runs in families, so if you have a mother or sister who has had HG in a pregnancy, you may be more likely to get it yourself.

If you have had HG in a previous pregnancy, you are more likely to get it in your next pregnancy than women who have never had it before, so it's worth planning in advance.

Treating hyperemesis gravidarum

There are medicines that can be used in pregnancy, including the first 12 weeks, to help improve the symptoms of HG. These include anti-sickness (anti-emetic) drugs, vitamins (B6 and B12) and steroids, or combinations of these.

You may need to try different types of medicine until you find what works best for you.

You can visit the Bumps website to find out which medicines are safe to use in pregnancy.

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.

Treatment can include intravenous fluids, which are given directly into a vein through a drip. If you have severe vomiting, the anti-sickness drugs may also need to be given via a vein or a muscle.

The charity Pregnancy Sickness Support has information and tips on coping with nausea and vomiting, including HG.

Will hyperemesis gravidarum harm my baby?

HG can make you feel very unwell, but it's unlikely to harm your baby if treated effectively.

However, if it causes you to lose weight during pregnancy, there is an increased risk that your baby may be born smaller than expected (have a low birthweight).

Other symptoms you may experience

Pregnancy Sickness Support is in touch with many women who have had HG, and who report having some or all of the following symptoms in addition to the main symptoms listed above: 

  • extremely heightened sense of smell
  • excessive saliva production
  • headaches and constipation from dehydration

If you experience these symptoms, you are not alone. Many women have them and they will go away when the HG stops or the baby is born.

How you might feel

The nausea and vomiting of HG can impact your life at a time when you were expecting to be enjoying pregnancy and looking forward to the birth of your baby.

It can affect you both emotionally and physically. The symptoms can be hard to cope with. Without treatment HG may also lead to further health complications, such as depression or tears in your oesophagus.

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

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

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

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.

Bear in mind that 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.

Another pregnancy

If you have had HG before, it's likely you will get it again in another pregnancy.

If you decide on another pregnancy, it can help to plan ahead, such as arranging child care so you can get plenty of rest.

You could try doing things that helped last time.

Talk to your doctor about starting medicine early.

Blood clots and hyperemesis gravidarum

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

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

Read more about how to prevent deep vein thrombosis.

Page last reviewed: 30 September 2019
Next review due: 30 September 2022