Hyperemesis Gravidarum

Hyperemesis Gravidarum (HG) is a severe form of Nausea and Vomiting of Pregnancy (NVP). It affects around 1-1.5% of all pregnant women. The cause (or causes) of HG remain unknown and there is no standard definition for the point at which NVP and HG meet, and no specific test that can diagnose it. However the most generally quoted symptoms leading to the diagnosis of HG include near constant nausea and frequent vomiting that is affecting your ability to function normally, weight-loss of more than 5%, dehydration, and malnutrition. What we do know about the causes of HG is that for many women there is a strong genetic element (women whose mother or sister suffered are more likely to get it themselves) and that it is not a psychological condition. Nothing you do or don’t do will cause HG to occur and it is not your fault that you are experiencing it.

What are the symptoms of HG?

In addition to the symptoms described above, HG typically presents itself with severe and persistent nausea and/or vomiting, leading to weakness and exhaustion. Some women vomit multiple times every day, others may vomit less frequently but suffer from nausea and dry retching that affects their ability to function. If nausea and/or vomiting is so severe that it affects your ability to carry out normal tasks such as eating, drinking, personal hygiene, or your ability to work or care for older children then it is worth contacting your GP or midwife.

In addition to feeling and being sick women with HG also can experience headaches, a very heightened and warped sense of smell, excessive saliva which is difficult to swallow, constipation and a number of other symptoms.

What are the risks associated with HG?

Since the introduction of IV hydration, HG is rarely the life-threatening illness it once was. However prolonged dehydration and malnutrition can lead to various health risks including vitamin deficiencies and electrolyte imbalances which need to be monitored and managed.

While recent research has shown that if HG is not effectively managed there may be increased risks to the baby, such as small for gestational weight gain and pre-term birth, it is important to remember that if treatment is sought and symptoms brought under control the risks to the baby are very low.

Increasingly research is showing that it is the malnutrition in early pregnancy that leads to complications, rather than the actual nausea and vomiting, so it’s important to seek help if sickness is stopping you eating.

What treatment options are available?

If a woman is becoming dehydrated because she cannot keep fluid down then it is important that she receive Intravenous fluid replacement (a drip). This is usually done in hospital but increasingly areas are offering outpatient rehydration which allows women to receive fluids during the day and return home at night.

There are a number of anti-sickness drugs which are used to treat NVP and HG. One, called Xonvea, is licensed in the UK. If that doesn’t work though there are lots of others which are not licensed for use in pregnancy but have been used for many years and no harmful effects for the baby have been found.

Many women can feel guilty about taking medication in pregnancy as there are long held beliefs that drugs should be avoided and may harm the baby but with a serious condition such as HG it is important to remember that NOT treating symptoms effectively can carry risk and many thousands of pregnant women have taken medication without harm to the baby.

Unfortunately many women suffering from HG encounter healthcare providers with limited knowledge or experience of treating HG and who may misdiagnose the symptoms as normal. This is often exacerbated by the difficulty in describing the severity of symptoms in a clear way, and so it can be helpful to keep a thorough record of symptoms.

Measuring and recording symptoms

There are several ways in which you can monitor your symptoms and produce an accurate record of the severity and need for treatment. These include:

Keeping a diary of what you eat and drink (including specific amounts of liquid)

Weighing yourself to check if you’re losing a lot of weight

Monitoring your urine output (try measuring it in a cheap plastic jug if you can)

Measuring vomiting episodes (how many per day, how long they last, what triggers an episode, and the amount you vomit if possible, e.g. less than a tablespoon or more than a cup full)

Keeping a diary of how you feel throughout the day (how many hours you feel nauseous, whether you have other symptoms such as acid reflux, what you have/have not managed to do)

Monitoring your mood (do you feel down, hopeless, depressed etc)

The amount of food and drink you manage to consume compared with the volume of both urine and vomit you produce can help create a clearer indication of the likelihood of dehydration.

Keeping a diary can help you recognise patterns in your symptoms. Sometimes women find that there is a period each day when the nausea is less intense and they can hydrate themselves easier by anticipating this. It is important to remember that the term “morning sickness” is both inaccurate and trivialises the condition. Most often women with NVP suffer from at least 2 episodes per day and some find that it is worse during the evening as being tired increases their symptoms.

Psychological effects

While we know that HG is not caused by psychological issues the condition can certainly cause them! Many women with HG suffer from antenatal depression, postnatal depression or post-traumatic stress disorder due to the severity of the condition and the weeks or months of isolation women can experience. A referral to the mental health team at any point during or after a pregnancy complicated by HG may help.

Coping with HG

Coping with HG can be very difficult for you and your family. You are in a period of excitement that you are having a child, yet you may feel miserable, confused and even guilty about how you feel, and not being able to work or undertake your normal activities. The main thing to emphasise is that you should not feel guilty. You have an illness that affects many women and there is nothing that you could have done to prevent it. Pregnancy Sickness Support suggests the following coping strategies:

Discuss with your doctor the possibility of taking anti-nausea medication

If taking medication, consider requesting suppositories or injections if you have difficulty keeping oral tablets down.

Avoid odours, especially of frying food and other strong smells. Even faint smells can be troublesome. If possible, encourage your partner to avoid cooking in the house.

Take plenty of rest and relaxation, activity always makes the symptoms of HG worse.

Enlist help and support: someone to care for your other children; someone to do the household chores etc.

Do not feel guilty. It is not your fault.

Avoid stress where possible.

Try to maintain fluid intake, but eat only when and if you feel like it.

What support is available?

The UK charity Pregnancy Sickness Support (PSS) has a helpline and webchat which is open Monday to Friday 9am-4.30pm and can offer information and support to women, their partners or family members. The charity also has a 1-2-1 support network of volunteers whom you can be matched with for support as well as a website forum for 24/7 support online.

 The importance of recognising and seeking help

Some women with HG feel that termination is their only option. Therefore it is crucial that the severity of symptoms is acknowledged as such and support and treatment is sought as soon as possible. Various treatment options are available and these should always be discussed with a GP or consultant.

Will I suffer from HG in future pregnancies?

Studies have shown that women who have suffered from HG in a previous pregnancy are more likely to suffer from it in subsequent pregnancies too. However a study carried out by the Motherisk Program in Canada suggests that pre-emptive therapy (i.e. starting anti-sickness medication prior to or at the very onset of symptoms) can limit the severity. This should be discussed with a consultant prior to trying to conceive another baby.

Further resources

In addition to the Pregnancy Sickness Support website there are a number of excellent online resources:

Spewing Mummy Blog

HER Foundation

NHS Choices

The Sick Film

There is a book on the market co-authored by UK Nurse Specialist Caitlin Dean (author of the Spewing Mummy blog and chairperson for PSS) called Hyperemesis Gravidarum – The Definitive Guide available from her website or Amazon.

Caitlin Dean has also written a book for children to explain why mummy is sick. It is called How to be an HG Hero and is available via her website.

With thanks

In partnership with Pregnancy Sickness Support

Last revised: January 2021