Sickness in pregnancy is common. Around 7 out of every 10 pregnant women experience nausea and/or vomiting, and this doesn't just occur in the morning.
For most women, this improves or disappears completely by around week 14, although for some women it can last longer.
Some pregnant women experience excessive nausea and vomiting. They might be sick many times a day and be unable to keep food or drink down, which can have a negative effect 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 in every 100.
If you are being sick frequently and can't 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 ("morning sickness").
Signs and symptoms of HG include:
- prolonged and severe nausea and vomiting – some women report being sick up to 50 times a day
- dehydration – not having enough fluids in your body because you can't keep drinks down; if you're drinking less than 500ml a day, you need to seek help
- ketosis – a serious condition that results in the build-up of acidic chemicals in the blood and urine; ketones are produced when your body breaks down fat, rather than glucose, for energy
- weight loss
- low blood pressure (hypotension) when standing
Unlike regular pregnancy sickness, HG may not get better by 14 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, ideally before you start suffering from 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 don't. 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 medications 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.
Evidence suggests that the earlier you start treatment, the more effective it will be. You may need to try different types of medication until you find what works best for you.
The UK teratology information service has a website called bumps (best use of medicines in pregnancy) where you can find out about the safety of specific medicines 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.
Will hyperemesis gravidarum harm my baby?
HG is unpleasant with dramatic symptoms, but the good news is 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 birth weight).
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 (ptyalism)
- headaches and constipation from dehydration
- pressure sores from long periods of time in bed
- episodes of urinary incontinence as a result of vomiting combined with the pregnancy hormone relaxin
If you experience these symptoms, you are not alone. Many women have them and, although they can be distressing, they will go away when the HG stops or the baby is born.
How you might feel
The nausea and vomiting of HG 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.
It can affect you both emotionally and physically. The symptoms not only make your life a misery, but may 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 don't know anyone who understands what it's like to have HG
- confused as to why this is happening to you
- 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 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.
Bear in mind that HG 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.
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.
Think back to what helped you last time – for example, specific drinks – and make sure you implement these measures this time around.
Talk to your doctor about starting medication 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