Nausea and Vomiting in Pregnancy

Nausea & Vomiting in Pregnancy

Patient Information

Obstetrics & Gynaecology Department

Introduction

The information in this leaflet is not intended to be a definitive guide but hopes to provide a basic understanding of the condition and its treatment.

What is nausea and vomiting in pregnancy?

In pregnant women, nausea and vomiting is common, affecting up to 90% of pregnancies.  The term morning sickness is often used to describe this condition when symptoms are relatively mild, temporary, and more troublesome than serious.

Causes and symptoms

Many things can cause nausea and vomiting during pregnancy, but a big reason is being very sensitive to a hormone that makes you throw up. This hormone is made by the placenta in the first half of pregnancy.

Symptoms usually start between weeks 4 and 7 and are often worst around week 9. Most women feel better by week 20, but for some, it can last longer or even throughout the whole pregnancy.

Other causes for your vomiting symptoms will be investigated, particularly if it starts only after 10 weeks of pregnancy, or if you have severe pain in your abdomen. Other possible causes include gastritis, kidney infection, stomach flu, or appendicitis.

What can I do to prevent or relieve the symptoms?

Although there is no evidence that nausea and vomiting in pregnancy can be prevented, vomiting during pregnancy sometimes may be lessened by lifestyle changes.

• Try to keep a positive attitude.  Nausea and vomiting usually stops after the first three or four months of pregnancy. 
• Ask family and friends for help with chores or childcare.
• Rest, especially after meals as tiredness may increase nausea.
• Always drink plenty of water, but little and often, to help avoid dehydration.
• Whilst nauseated, eat low-fat, bland foods such as potatoes, rice, or pasta.
• Avoid food or smells that trigger symptoms. 
• Have a snack as often as every hour or two during the day e.g. dry toast, plain biscuits etc.
• Eat a small snack at bedtime and when getting up to go to the bathroom in the middle of the night.

If your symptoms do not settle, see your GP, who can prescribe anti-sickness medications. These are safe to take in pregnancy.

Risks of prolonged nausea and vomiting

When morning sickness is much more prolonged and very severe, it leads to the clinical condition Hyperemesis gravidarum.  It is so severe for some women that it interferes with getting the fluid and nutrients they need; this causes severe dehydration and weight loss for the mother. 

Symptoms of Hyperemesis gravidarum may include:

• Severe nausea.
• Persistent and excessive daily vomiting.
• Inability to keep down any fluids.
• Weight loss.
• Light-headedness.
• Low blood pressure.
• Rapid heartbeat (tachycardia).
• Excessive salivation (ptyalism).

Will it harm my baby?

There is no evidence that nausea and vomiting will affect your baby. However, in women with severe nausea and vomiting, especially if the symptoms persist into the third trimester or if repeated admissions WERE required, there is an increased risk of having a baby with a lower-than-expected birthweight. In those cases, you may be offered scans to monitor the growth of the baby.

How is Hyperemesis gravidarum diagnosed?

Although many women with morning sickness feel like they are vomiting everything they eat, if they continue to gain weight and are not dehydrated, they do not have Hyperemesis gravidarum. Women with this condition will start to show signs of starvation, including weight loss.

Physical examination and laboratory tests of blood and urine samples will be used to help to look for any signs of dehydration. One of the most common ways used to help diagnosis and monitor Hyperemesis gravidarum, is using a questionnaire which will assess how severe your symptoms are. This asks questions about how often you feel sick, how many times you vomit or gag, and how these symptoms affect your daily life. A high score on the questionnaire along with signs of dehydration can mean that you have Hyperemesis Gravidarum. 

How is hyperemesis gravidarum treated?

As already discussed, the primary treatment for the problem of nausea and vomiting in pregnancy is dietary changes, but in severe cases, a combination of treatments and hospitalisation (this may only be for one day) is necessary.

When will I need to be admitted to the hospital?

Admission to the hospital will be advised if you: 

• are severely dehydrated or have weight loss and have a high score on the vomiting questionnaire
• cannot keep any fluid or medication down due to severe vomiting 
• have abnormal blood tests
• have an infection 
• have a chronic condition which requires you to take regular medications to remain well, for example: Diabetes, Epilepsy, HIV

What happens in the hospital? 

• On admission to hospital an intravenous infusion of fluids using appropriate amounts of salt, glucose and water will be used to correct the dehydration until vomiting is controlled.
• Prolonged vomiting can cause a deficiency of vitamins and so a vitamin supplement may be prescribed.
• Anti-sickness medication may be required to break the cycle of persistent vomiting. The medications used have been used to treat Hyperemesis gravidarum, without causing any long-term problems for the mother or infant.  You should consult your doctor for further information if you have any concerns about this issue.
• A scan may be arranged to confirm the pregnancy and to exclude the possibility of a twin pregnancy.
• Special stockings and blood thinner injections will be prescribed to help prevent blood clots. (Pregnant women are at increased risk of developing blood clots in their legs and lungs, especially if they are dehydrated or not moving round in the hospital due to sickness; blood thinner injections will reduce the risk.)
• Referral to a dietitian may be necessary in some cases.
• Referral to a psychotherapist or counsellor may be required in severe cases if the symptoms are so severe that the woman becomes depressed and needs extra support and counselling.

Finding a treatment that works in the management of nausea and vomiting in pregnancy is largely a matter of trial and error, and various combinations are used.  For many, it tends to be regarded as a minor disorder of pregnancy, but for others, it demands professional attention. 

Your doctor will recommend the most appropriate course of treatment based on your personal situation.  Feel free to discuss your care with a member of the medical or nursing team on Ward 2 at Leigh Infirmary or Swinley Ward at RAEI, or your midwife at any time. 

Following discharge from hospital, the nausea and vomiting may be controlled with lifestyle and dietary changes, and the occasional use of anti-sickness tablets. However symptoms may return or worsen. If this is the case and you do not already have a follow up appointment, you should contact the hospital.

Contact telephone numbers:

Ward 2 (Leigh Infirmary) 01942 264252 or 01942 264857, 8am until 4pm Monday to Friday.

Swinley Ward (RAEI, Wigan) 01942 822568, open 24 hours.

Further information sources 

Pregnancy Sickness Support: www.pregnancysicknesssupport.org.uk

NHS Choices: Nausea and morning sickness: www.nhs.uk/pregnancy/related-conditions/common-symptoms/vomiting-and-morning-sickness/

References

RCOG GTG 69: The Management of Nausea and Vomiting of Pregnancy and Hyperemesis Gravidarum https://www.rcog.org.uk/en/guidelines-research-services/guidelines/gtg69/