Many pregnant women feel sick or vomit during early pregnancy. In most cases it is mild and does not need any specific treatment. In more severe cases, an anti-sickness medicine is sometimes used. Low body fluid (dehydration) is a complication in severe cases. See a doctor if you suspect that you are becoming dehydrated.
What are sickness and vomiting in pregnancy?
Around half of all pregnant women feel sick and vomit during early pregnancy. So, it can be considered a normal part of pregnancy. It is often called morning sickness, but symptoms can occur at any time - not just in the morning. Symptoms are mild in most cases. Feelings of sickness (nausea) typically come and go. They usually last for between 1 and 4 hours at a time. Some women have more severe symptoms and have frequent and/or longer bouts of vomiting. You may just have nausea and no vomiting.
Sickness and vomiting usually start before the 9th week of pregnancy. In 9 out of 10 women, the symptoms have gone by 16 weeks of pregnancy. However, some pregnant women have some sickness throughout all of their pregnancy.
Sickness and vomiting in pregnancy can be a difficult problem to cope with. It can interfere with a pregnant woman's life. It can affect your mood, your work, your home situation and your ability to care for your family. Support and help from family and friends can make coping easier.
What is hyperemesis gravidarum?
For a minority of pregnant women (up to 2 in 100 pregnant women), the sickness and vomiting are prolonged and very severe. This causes them to become low in body fluid (dehydrated) and to lose weight. They may also develop vitamin deficiencies. Because they are not able to eat, the pregnant woman can develop signs of starvation. This is shown by looking for the presence of substances called ketones in the urine (using a simple test on a sample of urine). Ketones are produced if your body is forced to break down fat for energy if you are vomiting and are unable to keep food down.
This severe sickness and vomiting are known as hyperemesis gravidarum. These women often need to be admitted to hospital for intravenous fluids and other treatment.
What causes sickness and vomiting in pregnancy?
The exact cause of the sickness is not known. It is probably due to the hormonal changes of pregnancy. Nausea and vomiting tend to be worse in twin and other multiple pregnancies.
There are a number of risk factors that may make you more likely to experience nausea and vomiting in pregnancy. These include the following:
- If you are having a female baby.
- If this is your first pregnancy.
- If you have had - or your mother or sister has had - nausea and vomiting in previous pregnancies.
- If you are having twins or another multiple pregnancy.
- If you have a history of motion sickness.
- If you have a history of migraines.
- If you have experienced nausea when taking the combined oral contraceptive pill.
- If you are stressed or anxious about something.
- If you are obese.
- If you are a younger woman.
Do sickness and vomiting affect the baby?
Not usually. The baby gets nourishment from your body's reserves even though you may not eat well when you are vomiting. The effort of retching and vomiting does not harm your baby. In fact, some studies have shown that having sickness and vomiting in early pregnancy is a good indication that your pregnancy is healthy and will have a successful outcome.
Your baby may be affected if you develop hyperemesis gravidarum and become very ill with low body fluid (dehydration) which is not treated. In this case, the most likely problem is that your baby will have a low birth weight when he or she is born. However, not all babies born to women with hyperemesis gravidarum have a low birth weight.
Do I need any investigations?
If you have mild nausea and vomiting during pregnancy, you do not usually need any specific tests or investigations. Investigations may be needed:
- If your symptoms become more severe.
- If you are not able to keep any food or fluids down.
- If you start losing weight.
Investigations may include a urine test to look for ketones in your urine (as described above) and some blood tests.
What can I do to help relieve sickness and vomiting?
In most cases, as the symptoms are often mild, no specific treatment is needed. However, there are certain things that you may like to try to help relieve your symptoms. They include the following:
- Eating small but frequent meals may help. Foods high in carbohydrate are best, such as bread, crackers, etc. Some people say that sickness is made worse by not eating anything at all. If you eat some food regularly, it may help to ease symptoms. Eating a plain (or ginger) biscuit about 20 minutes before getting up is said by some women to help. Cold meals may be better if nausea is associated with food smells.
- Ginger. Some studies have shown that taking ginger tablets or syrup may be effective for relieving nausea and vomiting in pregnancy. However, care should be taken, as the quality of ginger products varies and they are not closely regulated in the UK. Before you take a ginger product, you should discuss this with a pharmacist or your GP.
- Avoiding triggers. Some women find that a trigger can set off the sickness. For example, a smell or emotional stress. If possible, avoid anything that may trigger your symptoms.
- Having lots to drink to avoid low body fluid (dehydration) may help. Drinking little and often rather than large amounts may help to prevent vomiting. Try to aim to drink at least two litres a day. Water is probably the best drink if you are feeling sick. Cold and sweet drinks can sometimes make symptoms worse in some people.
- Rest. Make sure that you have plenty of rest and sleep in early pregnancy. Being tired is thought to make nausea and vomiting during pregnancy worse.
- Acupressure. Some studies have shown that P6 (wrist) acupressure may be effective for relieving nausea and vomiting in pregnancy. Acupressure is the application of pressure only and does not need needles.
Note: generally, you should not use over-the-counter remedies for sickness and vomiting whilst you are pregnant. This is because their safety and effectiveness for sickness and vomiting in pregnancy is uncertain.
When are anti-sickness medicines needed?
Most pregnant women manage to eat and drink enough and they don't need anti-sickness medicines. However, an anti-sickness medicine may be advised if your symptoms are persistent and severe, or do not settle with the above measures.
It is generally best to avoid medicines when you are pregnant (including herbal remedies, as the contents are often uncertain). However, some medicines have been used for a number of years to treat sickness and vomiting in pregnancy and are thought to be safe. For example, many women have used promethazine or cyclizine and there is no evidence that they harm a developing baby. There are some others if these are not helpful.
Always see a doctor before taking an anti-sickness medicine when you are pregnant. It is best to use medication for the shortest time possible. However, for some women, medication may be needed for several weeks before symptoms settle.
What if these treatments do not work very well?
Hospital care is needed to give fluids by a drip in a small number of women. Hospital care may be needed if you do not respond to medication, become ill, lose weight or become low in body fluid (dehydrated).
Other causes of vomiting
Remember, not all vomiting may be due to the pregnancy. You can still get other illnesses such as a urinary tract infection. You should see a doctor urgently if you develop any symptoms that you are worried about, particularly any of the following symptoms:
- Very dark urine, or not passing any urine for more than eight hours.
- Stomach pains.
- High temperature (fever).
- Pain on passing urine.
- Jaundice (yellow skin).
- Severe weakness or feeling faint.
- Blood in your vomit.
- Repeated, unstoppable vomiting.
Further reading & references
- Antenatal care; NICE Clinical Guideline (March 2008)
- Jarvis S, Nelson-Piercy C; Management of nausea and vomiting in pregnancy. BMJ. 2011 Jun 17;342:d3606. doi: 10.1136/bmj.d3606.
- Matthews A, Dowswell T, Haas DM, et al; Interventions for nausea and vomiting in early pregnancy. Cochrane Database Syst Rev. 2010 Sep 8;(9):CD007575.
- Wegrzyniak LJ, Repke JT, Ural SH; Treatment of hyperemesis gravidarum. Rev Obstet Gynecol. 2012;5(2):78-84.
- Nausea and vomiting in pregnancy, Prodigy (May 2008)
Disclaimer: This article is for information only and should not be used for the diagnosis or treatment of medical conditions. EMIS has used all reasonable care in compiling the information but make no warranty as to its accuracy. Consult a doctor or other health care professional for diagnosis and treatment of medical conditions. For details see our conditions.
Dr Tim Kenny
Dr Colin Tidy
Dr John Cox