What is nausea and vomiting of pregnancy?
Nausea and vomiting is a symptom of pregnancy and affects most women to some degree. It begins early in pregnancy, most commonly between the 4th and 7th week. It usually settles by 12–14 weeks, although in some women it may last longer. It is often called ‘morning sickness’ but it can occur at any time of the day or night. The cause is thought to be pregnancy hormones but it is unclear why some women get it worse than others. However, it is more likely if:
- you have had it before
- you are having more than one baby (twins or triplets)
- you have a molar pregnancy (a rare condition where the placenta overgrows and the baby does not form correctly).
It is important that other causes of vomiting are considered and looked into, particularly if you are unwell, have pain in your tummy or your vomiting only starts after 10 weeks of pregnancy. Possible other causes include gastritis (inflammation of the stomach), a kidney infection, appendicitis or gastroenteritis.
What is hyperemesis gravidarum (HG)?
If the nausea and vomiting becomes so severe that it leads to dehydration and significant weight loss, it is known as HG. It may affect 1 to 3 in 100 pregnant women. Signs of dehydration include feeling ‘dry’ or very 2 thirsty, becoming drowsy or unwell, or your urine changing from a light yellow to a dark yellow or brown colour. Women with this condition may need to be admitted to hospital. In severe cases, vomiting can last up to 20 weeks. Occasionally, it can last until the end of pregnancy.
What are the symptoms of HG?
Nausea and vomiting of pregnancy can be a difficult problem to cope with. It can affect your mood, your work, your home situation and your ability to care for your family. In some women, the symptoms can be so severe that they become depressed and need extra support such as counselling. If you find that you persistently feel down, then you should speak to your obstetrician.
Will hyperemesis gravidarum harm your baby?
There is no evidence that nausea and vomiting has a harmful effect on your baby. In fact, you have a slightly lower risk of miscarriage. Women with severe nausea and vomiting or with HG may, however have a baby with a lower than expected birthweight, therefore you may be offered scans to monitor the growth of your baby.
How can you manage your symptoms?
Most women with nausea and vomiting of pregnancy will be able to manage their symptoms themselves.
You should:
-Eat small amounts often – meals that are high in carbohydrate and low in fat, such as potato, rice and pasta, are easier to tolerate; try plain biscuits or crackers.
-Avoid any foods or smells that trigger symptoms.
– Some women find eating or drinking ginger products helps. You could try ginger biscuits, crystallised ginger or ginger herbal tea. However, this may irritate your stomach.
–Rest. When you are tired the sickness can get worse.
-Avoid foods with lots of sugar or saturated fats such as sweets, chocolate and red meat.
– Carbohydrates – things like bread, rice, potatoes and pasta can be easier to eat when you’re feeling nauseous.
– Have a small snack before getting up in the morning – something like dry toast or crackers.
What happens when you attend the clinic?
If your symptoms do not settle with the above advice then you should contact your obstetrician. You will have a check-up that may include a discussion about how long you have had your symptoms for and whether you are keeping fluids and food down. Your obstetrician will also check your observations (temperature, pulse, respiratory rate and blood pressure), your weight and perform an assessment of whether you are dehydrated (urine tests, blood tests) and an ultrasound scan to check how many weeks pregnant you are.
If you are able to tolerate some fluids but are unable to drink enough, you should be offered fluids through a drip in your arm over a short period of time and you will also be given ant sickness medication.
Will you need to be admitted to hospital?
Admission to hospital may be advised if you are dehydrated (having ketones in your urine is a sign of dehydration), you have severe vomiting and are unable to tolerate any fluids, if your blood tests are abnormal and you have lost weight.
What happens in the hospital?
You will be given the fluids you need though a drip in your arm. This will be continued until you are able to drink fluids without vomiting. Each day your fluid intake and how much urine you are passing will be recorded. Your temperature, blood pressure, pulse, respiratory rate and weight will also be recorded. You should be offered: • anti-sickness medication and a B vitamin called thiamine; both of these can be given through the drip in your arm if you are unable to keep tablets down • special stockings (graduated elastic compression stockings) to help prevent blood clots • heparin injections (to thin your blood). Pregnant women are at increased risk of developing blood clots in their legs, called deep vein thrombosis (DVT) or in their lungs (called pulmonary embolism). Being dehydrated and not being mobile increases this risk further. Heparin injections reduce this risk. You will be advised to continue these until you leave hospital and sometimes for longer If you are taking iron medication, this will be stopped because it can make sickness worse. When you are feeling better, you can start to drink and eat small amounts and slowly build up to a normal diet.
What anti-sickness medication will you be offered?
There are a variety of anti-sickness medicines that you may be offered. Not all of the medicines listed below are licensed for use in pregnancy, but there is no evidence that they are harmful to your baby. It is worth considering taking them if other measures have not helped.
– Cyclizine is the medication that is usually given first. It can be taken in tablet form or by an injection.
– Prochlorperazine and metoclopramide can be tried if cyclizine has not worked. All three of these medications are considered to be safe in pregnancy.
-Ondansetron is another medication that may be prescribed for nausea and vomiting and can be taken by mouth or by injection.
– Corticosteroids may be considered if you are still suffering from HG despite fluids being given through a drip or if the above anti-sickness medication has not helped.
Corticosteroids are successful in many women where all other measures have failed. Most women will be able to stop corticosteroids by 18–20 weeks but 1 in 5 women will need to continue them at a low dose for the rest of the pregnancy. Only a tiny amount of the corticosteroids used to treat HG passes from you to your baby and they are generally considered safe for use in pregnancy. If HG is not treated, it may cause more harm to the baby than any possible effects of a medicine recommended by your doctor.
Dr Efterpi Tingi
Consultant Obstetrician and Gynaecologist
