Morning sickness

Symptoms of nausea, vomiting and tiredness are common during early pregnancy. Around half of all pregnant women will experience both nausea and vomiting, and 28% of women will experience nausea without vomiting.

Nausea and vomiting in pregnancy (NVP)

Nausea and vomiting in pregnancy (NVP) is an unwelcome, but perfectly normal, part of pregnancy and it does not put your baby at any increased risk.

Studies have shown that women who have NVP tend to have healthier pregnancies, with lower rates of miscarriages and still births, compared to women who have nausea-free pregnancies.

NVP can often be treated by making changes to your diet and by taking plenty of rest.

NVP is sometimes trivialized as a minor inconvenience of pregnancy, but it can have a significant, adverse affect on your day-to-day activities and quality of life. The support of friends and family may help you to cope better with this upsetting condition.

Although commonly called morning sickness, nausea and vomiting in pregnancy (NVP) can occur at any time during the day.

For most women, the symptoms of NVP usually begin before the ninth week of pregnancy, around six weeks after their last period.

The symptoms of NVP should improve as your pregnancy progresses and, in about 90% of cases, symptoms resolve by the fourth month of pregnancy.

When to seek urgent medical advice

Rarely, symptoms of nausea and vomiting may be caused by a more serious condition, such as a urinary tract infection, or appendicitis. You should immediately contact your GP, midwife, or NHS Direct on 0845 46 47 if you:

• have very dark coloured urine, or you do not pass urine for more than eight hours,
• have abdominal pain and fever,
• feel severely weak, or faint,
• vomit blood,
• have repeated, unstoppable vomiting, or
• you are unable to keep down food, or fluids, for 24 hours.

The exact cause of nausea and vomiting in pregnancy (NVP) is unknown. However, a number of theories have been suggested which are outlined below.

Hormones

Changes in hormone levels during the early stages of pregnancy may cause short-term nausea and vomiting.

During pregnancy, oestrogen levels rise and tend to be at their highest in the first three months, when the symptoms of NVP are at their worst.

Rising levels of oestrogen may heighten your sense of smell, which may explain why certain smells can trigger the onset of symptoms.

Evolutionary adaptation

Evolutionary adaptation is a change that occurs in an organism in order to make it better adapted to its environment.

Some scientists believe that NVP is an evolutionary adaptation that has occurred in order to protect women and their baby from food poisoning.

Pregnant women with NVP often do not feel like eating foods that can potentially become contaminated, such as meat, poultry, and eggs, instead preferring foods which have a low risk of contamination, such as bread, or crackers.

Nausea and vomiting in pregnancy (NVP) can usually be diagnosed on the basis of the symptoms alone.

If you are experiencing very severe vomiting, your GP may recommend that you have a urine test. This is to check for the presence of ketones, which are often found in the urine if the body is forced to break down fat for energy.

If high levels of ketones are found in your urine, it may be a sign that the severe vomiting is causing you to become malnourished and, if this is the case, you will require extra nutrients, and possibly medicine to help prevent further vomiting.

Self-care

There are a number of dietary and lifestyle changes that you can make which can help reduce the symptoms of nausea and vomiting in pregnancy (NVP). These changes are outlined below.

• Make sure that you get plenty of rest because tiredness can make the nausea worse.
• Drink little and often, rather than in large amounts, because this may help to prevent vomiting.
• Eat small, frequent meals that are high in carbohydrate and low in fat. For example, savoury foods, such as toast, crackers, or crisp-bread, are usually better tolerated than sweet, or spicy, foods.
• Eat cold meals, rather than hot meals because cold meals do not give off the smell that may provoke nausea.
• Eat plain biscuits 20 minutes before getting up.
• Avoid any food, or smells, that trigger your symptoms.
• Avoid drinking drinks that are cold, tart (sharp or bitter tasting), or sweet.

Medical treatment

If changing your diet and lifestyle do not work, and your symptoms of nausea and vomiting are severe, your GP may recommend a short-term course of a suitable anti-sickness medicine which is safe to use in pregnancy. This type of medicine is called an anti-emetic and it helps to prevent vomiting.

Other treatments

The spice ginger is not recommended as a treatment for NVP. While there is some evidence to suggest that it can help to relieve symptoms, not enough is known about the risks of any possible long-term effect on pregnant women and their baby. Also, ginger products are not regulated in the UK and their quality can vary considerably.

The use of other herbal supplements, multivitamins, and the over-the-counter (OTC) remedy, pyridoxine (Vitamin B6), are also not recommended for the same reasons.

Hyperemesis gravidarum

Hyperemesis gravidarum is a rare, but severe form of nausea and vomiting in pregnancy. It is estimated to affect between 0.5-2% of pregnant women. In 90% of women who have hyperemesis gravidarum, the symptoms resolve by the fifth month of pregnancy.

The symptoms of hyperemesis gravidarum are usually so severe that it is impossible for you to keep any fluids down. Excessive vomiting can cause dehydration and weight. loss.

Therefore, if your symptoms of nausea and vomiting are so severe that you are unable to tolerate fluids, you should seek urgent medical advice as soon as possible.

Your GP may recommend that you be admitted to hospital so that your condition can be assessed and the appropriate treatment can be given.

If you have hyperemesis gravidarum, it is unlikely to cause harm to your baby, but if it causes reduced weight gain in pregnancy, there is an increased risk that your baby may be born with a low birth weight.

CKS Guidelines (2008) Nausea and sickness in pregnancy

Festin, M. (2006). Nausea and vomiting in early pregnancy. BMJ Clinical Evidence

Jewell, D., Young ,G.(2003). Interventions for nausea and vomiting in early pregnancy. Cochrane Database of Systematic Reviews 2003, Issue 4. Art. No.: CD000145. DOI: 10.1002/14651858.CD000145.

The Society of Obstetricians and Gynaecologists of Canada (2002). The Management Of Nausea And Vomiting Of Pregnancy

Wilcox, R.S. (2006). Pregnancy, Hyperemesis Gravidarum. eMedicine.com

Available online at: http://www.emedicine.com/emerg/TOPIC479.HTM