Vomiting and sickness when pregnant
Nausea and vomiting in pregnancy (NVP), also known as morning sickness, is very common in the early weeks of pregnancy. It doesn’t put your baby at any increased risk, and usually clears up between weeks 12 and 14 of pregnancy.
Some women get a very severe form of nausea and vomiting, called hyperemesis gravidarum (HG). It's sometimes called extreme morning sickness, and it can be very serious. HG needs specialist treatment, sometimes in hospital. Find out more about hyperemesis gravidarum.
With morning sickness, some women are sick (vomit) and some have a feeling of sickness (nausea) without being sick. The term ‘morning sickness’ is misleading. NVP can affect you at any time of the day or night, and some women feel sick all day long. It’s thought that hormonal changes in the first 12 weeks are probably one of the causes of morning sickness.
Nausea can be one of the most trying problems in early pregnancy. It comes at a time when you may be feeling tired and emotional, and when many people around you may not realise you're pregnant and expect you to be your normal self.
For most women, the symptoms of nausea and vomiting usually begin before they’re nine weeks pregnant, around six weeks after their last period. Symptoms are feeling sick and sometimes vomiting. The symptoms of NVP should improve as your pregnancy progresses. In 9 out of 10 women, symptoms disappear by the third month of pregnancy. However, some women experience nausea and vomiting for longer than this, and about one woman in 10 continues to feel sick after week 20.
How common is morning sickness (NVP)?
During early pregnancy, nausea, vomiting and tiredness are common symptoms. Around half of all pregnant women experience nausea and vomiting, and around three in 10 women experience nausea without vomiting.
People sometimes consider morning sickness a minor inconvenience of pregnancy, but for some women it can have a significant adverse effect on their day-to-day activities and quality of life.
Treating morning sickness (NVP)
If you have morning sickness, your GP or midwife will initially recommend that you try a number of changes to your diet and daily life to help reduce your symptoms. These include:
- getting plenty of rest because tiredness can make nausea worse
- if you feel sick first thing in the morning, give yourself time to get up slowly – if possible, eat something like dry toast or a plain biscuit before you get up
- drinking plenty of fluids, such as water, and sipping them little and often rather than in large amounts, because this may help prevent vomiting
- eating small, frequent meals that are high in carbohydrate (such as bread, rice and pasta) and low in fat – most women can manage savoury foods, such as toast, crackers and crispbread, better than sweet or spicy foods
- eating small amounts of food often rather than several large meals, but don’t stop eating
- eating cold meals rather than hot ones because they don’t give off the smell that hot meals often do, which may make you feel sick
- avoiding foods or smells that make you feel sick
- avoiding drinks that are cold, tart (sharp) or sweet
- asking the people close to you for extra support and help – it helps if someone else can cook but if this isn’t possible, go for bland, non-greasy foods, such as baked potatoes or pasta, which are simple to prepare
- distracting yourself as much as you can – often the nausea gets worse the more you think about it
- wearing comfortable clothes without tight waistbands, which can sometimes make you feel uncomfortable
If you have severe NVP, your doctor or midwife might recommend medication. Some other possible treatments that you may find useful are listed below.
Anti-sickness medication (antiemetics)
If your nausea and vomiting is severe and doesn’t improve after you make changes to your diet and lifestyle, your GP may recommend a short-term course of an anti-sickness medicine that is safe to use in pregnancy. This type of medicine is called an antiemetic, which means it helps to prevent nausea and vomiting. The commonly prescribed antiemetics can have side effects. These are rare, but can include muscle twitching.
Some antihistamines (medicines that are often used to treat allergies such as hay fever) also work as antiemetics. Your doctor might prescribe an antihistamine that is safe to take in pregnancy. See your GP if you would like to consider this form of treatment.
There is some evidence that ginger supplements may help reduce the symptoms of nausea and vomiting in some pregnant women. To date, there have not been any reports of adverse effects being caused by taking ginger during pregnancy. However, ginger products are unlicensed in the UK, so buy them from a reputable source, such as a pharmacy or supermarket. Check with your pharmacist before you use ginger supplements. You can find out more about vitamins and supplements in pregnancy.
Some women find that ginger biscuits or ginger ale can help reduce nausea. You can try different things to see what works for you.
The National Institute for Health and Clinical Excellence (NICE) advises that acupressure on the wrist may be effective in reducing symptoms of nausea in pregnancy. Acupressure involves wearing a special band or bracelet on your forearm. Some researchers have suggested that putting pressure on certain parts of the body may cause the brain to release certain chemicals that help reduce nausea and vomiting.
There have been no reports of any serious adverse effects caused by using acupressure during pregnancy, although some women have experienced numbness, pain and swelling in their hands.
When to seek medical advice
If you are vomiting and can’t keep any food or drink down, there is a chance that you could become dehydrated or malnourished. Contact your GP or midwife immediately if you:
- have very dark-coloured urine or do not pass urine for more than eight 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 (100.4°F) or above
- vomit blood
Urinary tract infections (UTIs) can also cause nausea and vomiting. A UTI is an infection that usually affects the bladder but can spread to the kidneys.
If you have any pain when passing urine or you pass any blood, you may have a urine infection and this will need treatment. Drink plenty of water to dilute your urine and reduce pain. You should contact your GP within 24 hours. If you’re worried about your symptoms, you can call NHS Direct on 0845 46 47 to speak to a medical adviser.
What causes morning sickness (NVP)?
The exact cause of nausea and vomiting in pregnancy (NVP) is unknown. However, research has suggested a number of different causes, including:
Increased oestrogen and progesterone
Changes in levels of the female sex hormones (oestrogen and progesterone) during the early stages of pregnancy may cause short-term nausea and vomiting. Oestrogen levels tend to be at their highest during the first 12 weeks of pregnancy when the symptoms of NVP are worst.
Rising levels of oestrogen can heighten your sense of smell, which may explain why certain smells – such as food cooking – can make you feel sick. As progesterone production increases, there is less movement in your small intestine, oesophagus (food pipe) and stomach, causing NVP. The reduction in movement occurs as a result of the muscle walls relaxing.
After conception (when the sperm fertilises the egg), the body begins to produce a hormone called human chorionic gonadotrophin (hCG). It is thought that a rise in the level of hCG may cause nausea and vomiting during pregnancy.
A lack of vitamin B6 in the diet is thought to be another possible cause of morning sickness, and there is evidence that B6 can help to relieve symptoms. Foods that contain vitamin B6 include:
- whole cereals, such as oatmeal, wheat germ and brown rice
- wholemeal bread
- soya beans
It is thought that a lack of vitamin B6 may cause hyperemesis gravidarum, an uncommon but severe form of nausea and vomiting in pregnancy. It requires a stay in hospital as vomiting can make you dehydrated.
You should be able to get enough vitamin B6 through a healthy, balanced diet. Further evidence is needed to establish the benefits of taking vitamin B6 supplements during pregnancy. Although vitamin B6 appears to be effective at reducing the symptoms of NVP, there is limited evidence regarding how safe it is to take during pregnancy.
Don’t take any over-the-counter remedies or supplements without talking to your midwife, GP or pharmacist first.
A number of different factors may mean you are more likely to have NVP. These include:
- nausea and vomiting in a previous pregnancy
- your unborn baby being a girl
- a family history of NVP or morning sickness
- a history of motion sickness, for example in a car
- a history of nausea while using contraceptives that contain oestrogen
- obesity – where you have a body mass index (BMI) of 30 or more
- multiple pregnancies, such as twins or triplets
- first pregnancy
Some pregnant women experience severe nausea and vomiting. This condition is known as hyperemesis gravidarum (HG) and needs specialist treatment. HG isn’t common but it can be severe, usually needing hospital treatment. If you're being sick all the time and can't keep food down, tell your midwife or doctor as soon as possible.
Symptoms of hyperemesis gravidarum include:
- prolonged and severe nausea and vomiting
- ketosis – a serious condition that is caused by a raised number of ketones in the blood and urine (ketones are poisonous acidic chemicals which are produced when your body breaks down fat, rather than glucose, for energy)
- weight loss
- low blood pressure (hypotension) when standing up
The symptoms can have a significant effect on your life and may lead to further complications, such as depression.
The symptoms of HG are usually so severe that it is impossible to keep any fluids down, and this can cause dehydration and weight loss. Dehydration is when you don’t have enough fluids in your body.
Healthtalkonline has videos and written interviews of women talking about their experiences of hyperemesis gravidarum, and how they coped.
Treating hyperemesis gravidarum
HG needs specialist treatment, and you usually need to be admitted to hospital so that doctors can assess your condition and give you appropriate treatment. This can include intravenous fluids (to treat the ketosis) and antiemetic treatment to stop the vomiting.
HG is unlikely to cause harm to your baby. However, if it causes weight loss during pregnancy there is an increased risk that your baby may be born smaller than expected.
Deep vein thrombosis
Because HG can cause dehydration, there is also an increased risk of deep vein thrombosis. Deep vein thrombosis (DVT) is a blood clot in one of the veins in the body, such as in your leg.