Treating nausea and vomiting in pregnancy
(Date of issue: December 2013. Version: 1.3)
This factsheet has been written for members of the public by the UK Teratology Information Service (UKTIS). UKTIS is a not-for-profit organisation funded by Public Health England on behalf of UK Health Departments. UKTIS has been providing scientific information to health care providers since 1983 on the effects that medicines, recreational drugs and chemicals may have on the developing baby during pregnancy.
What is morning sickness?
Nausea and vomiting are commonly experienced in early pregnancy and are often referred to as ‘morning sickness’ but can occur at any time of the day. Most women who are affected experience these symptoms between week 6 and 16 of pregnancy, but some suffer throughout pregnancy. A small number of women experience very severe pregnancy sickness; this is called hyperemesis gravidarum and may require hospitalisation and rapid rehydration with intravenous fluids.
What are the treatments for nausea and vomiting in pregnancy?
Numerous ‘home remedies’ have been used by pregnant women for centuries; an example of which is ginger. Some women also use acupressure bands that are designed to help with travel sickness. If you feel your symptoms are too bad to cope with you should ask your doctor for advice as several anti-sickness medicines are available. There is, as yet, no good scientific evidence as to which treatments or combinations of treatments are the most effective for treating pregnancy sickness.
Although many medicines used in the treatment of nausea and vomiting are not officially licensed for use in pregnancy, most have been used in pregnancy without any known adverse effects on the developing baby. It is very important that you do not become dehydrated or unhealthy as a result of pregnancy sickness: a healthy mother is very important for the healthy development of a baby.
Make sure you ask your doctor or healthcare provider for information on any medicine that is prescribed or suggested in pregnancy.
Are there any problems caused by taking treatments for nausea and vomiting in pregnancy?
There is no evidence to suggest that use of ginger-containing products or acupressure during pregnancy will harm your baby.
Promethazine (Phenergan,® Sominex,® Avomine®) and cyclizine
Promethazine and cyclizine are commonly used to treat nausea and vomiting in pregnancy. Studies on the use of cyclizine and promethazine in pregnancy have not shown that these medicines will increase the chance of having a baby with a birth defect.
Prochlorperazine (Buccastem,® Stemetil®) and metoclopramide (Maxolon®)
There is not much pregnancy safety information for prochlorperazine and metoclopramide, but the scientific information that is available so far does not show that either of these two medicines is harmful to a developing baby when used in pregnancy.
Two studies have suggested that women who took ondansetron during the first three months of pregnancy were more likely to have a baby with a heart defect than women who did not take ondansetron in pregnancy. A single study has also suggested a possible link between ondansetron use in pregnancy cleft palate in the baby. Other studies have, however, not agreed with these findings. More detailed information about women who have taken ondansetron in early pregnancy and their babies therefore needs to be collected and studied.
Where available, you may wish to read the bumps leaflets on the medicines listed for more detailed information.
Corticosteroids or ‘steroids’ are sometimes prescribed for women with very severe pregnancy sickness associated with weight loss and which has not responded to other treatments. Some studies have shown that use of corticosteroids in early pregnancy may increase the risk of having a baby with a cleft lip and palate, or that use in other stages of pregnancy may reduce the growth of a baby in the womb (intrauterine growth retardation), however other studies have not shown these effects. Because the findings of these studies do not agree it is difficult to say whether these risks are real and whether they only occur with higher doses of steroids or if steroids are taken for a certain length of time in pregnancy. However, if hyperemesis gravidarum is not treated it may cause more harm to the baby than the possible effects of a medicine recommended by your doctor. Every pregnancy is different and your doctor is the best person to help you to make the most appropriate treatment choice for you and your baby.
Will my baby need extra monitoring during pregnancy?
As part of their routine antenatal care, most women will be offered a scan at around 20 weeks of pregnancy to look for birth defects and to check the baby’s growth.
The need for additional tests or monitoring during pregnancy will depend on how unwell the mother is and what medicines she has taken. For most anti-sickness treatments no extra monitoring during your pregnancy will be necessary. However, if you have been taking corticosteroids for hyperemesis gravidarum for longer than three weeks your obstetrician may recommend closer monitoring of your baby’s growth.
Who can I talk to if I have questions?
If you have any questions regarding the information in this leaflet please discuss them with your health care provider. They can access more detailed medical and scientific information from www.UKTIS.org.
Up to 1 out of every 5 pregnancies ends in a miscarriage, and 1 in 40 babies are born with a birth defect. These are referred to as the background population risks. They describe the chance of these events happening for any pregnancy before taking factors such as the mother’s health during pregnancy, her lifestyle, medicines she takes and the genetic make up of her and the baby’s father into account.
Medicines use in pregnancy
Most medicines used by the mother will cross the placenta and reach the baby. Sometimes this may have beneficial effects for the baby. There are, however, some medicines that can harm a baby’s normal development. How a medicine affects a baby may depend on the stage of pregnancy when the medicine is taken. If you are on regular medication you should discuss these effects with your doctor/health care team before becoming pregnant.
If a new medicine is suggested for you during pregnancy, please ensure the doctor or health care professional treating you is aware of your pregnancy.
When deciding whether or not to use a medicine in pregnancy you need to weigh up how the medicine might improve your and/or your unborn baby’s health against any possible problems that the drug may cause. Our bumps leaflets are written to provide you with a summary of what is known about use of a specific medicine in pregnancy so that you can decide together with your health care provider what is best for you and your baby.
Every pregnancy is unique. The decision to start, stop, continue or change a prescribed medicine before or during pregnancy should be made in consultation with your health care provider. It is very helpful if you can record all your medication taken in pregnancy in your hand held maternity records.