Chloroquine for prevention and treatment of malaria

Date: February 2019, Version 3

What is it?

Chloroquine (Avloclor®, Malarivon®, Nivaquine®) is a medicine that is taken either on its own or in combination with other antimalarial medicines to:

• prevent malaria infection when travelling to certain parts of the world where malaria is common
• treat a person who has been infected with malaria 

Malaria is a serious illness that is spread by mosquito bites and can result in death. Malaria infection in pregnancy can be dangerous to the health of both mother and baby. Pregnant women are therefore advised to avoid travelling to areas where there is a risk of catching malaria. If you are pregnant or planning a pregnancy and cannot avoid travelling to a high risk malaria area ask your doctor for advice as soon as possible. You may need to start taking an antimalarial medicine a few weeks before you travel. Your doctor is the best person to help you decide what is right for you and your baby.

Is it safe to take chloroquine in pregnancy?

There is no evidence that chloroquine is harmful to an unborn baby, although more information about its use in pregnancy ideally needs to be collected. If you are travelling to certain regions you may be advised to take chloroquine. You should not avoid taking chloroquine because you are pregnant. The risk of harm to you and your baby from malaria is likely to be far greater than any potential risk from taking chloroquine. Chloroquine does not protect against malaria in all areas of the world and you should always ask your healthcare provider for up-to-date advice on the most appropriate antimalarial to suit your travel plans.

No antimalarial medicine is 100% effective and it is very important that you also reduce the chance of being bitten by using insect repellents, mosquito nets, and covering as much skin as possible with clothing, particularly between dusk and dawn. Please read our bumps leaflet on insect repellents for more information on which products are advised for use in pregnancy.

Can taking chloroquine in pregnancy cause a miscarriage?

Seven studies investigated the chance of miscarriage in a total of 5,300 women taking chloroquine. None of these studies found an increased chance of miscarriage with chloroquine use. Although this is reassuring, miscarriage has been studied in only a small number of women specifically taking chloroquine in early pregnancy when miscarriage is most likely to occur. More research is therefore ideally required to confirm that use of chloroquine at this stage of pregnancy is not harmful. However, malaria infection during early pregnancy is itself known to increase the chance of miscarriage, and any possible risk from taking chloroquine is likely to be less than the risks posed to both mother and baby by malaria.

Can taking chloroquine in pregnancy cause my baby to be born with birth defects?

A baby’s body and most internal organs are formed during the first 12 weeks of pregnancy. It is mainly during this time that some medicines are known to cause birth defects.

There is currently no scientific evidence to suggest that women who take chloroquine in pregnancy have a higher chance of having a baby with a birth defect. Although this is reassuring, the chance of birth defects has been studied in only a small number of babies exposed to chloroquine in the first trimester. More research is therefore ideally required to confirm that use of chloroquine specifically at this stage of pregnancy does not affect a baby’s development. However, any possible risk from taking chloroquine is likely to be less than the risks posed to both mother and baby by malaria.

Can taking chloroquine in pregnancy cause preterm birth?

Chloroquine use in pregnancy has not been shown to cause a baby to be born early in any of the four studies that have investigated this. Studies have, however, shown that preterm birth is more common in pregnant women with malaria infection. 

Can taking chloroquine in pregnancy cause my baby to be small at birth (low birth weight)?

Eleven studies have investigated whether chloroquine use in pregnancy may affect a baby’s birth weight. Eight of these studies showed that women taking chloroquine did not have a higher chance of having a baby with a low birth weight (<2,500 g). The remaining three studies found that women taking chloroquine were more likely to have low birth weight babies than women taking other antimalarial medicines. However, in the areas where these studies were carried out, chloroquine may have been less effective at preventing malaria than the other medicines, meaning that more of the pregnant women taking chloroquine had malaria, which is known to be linked to having a low birth weight baby. It is therefore likely that the malaria infection (and not the chloroquine) was the reason these studies found that more babies weighed less than 2,500 g at birth.

Can taking chloroquine in pregnancy cause stillbirth?

No increased chance of stillbirth was seen in any of the studies of pregnant women taking chloroquine that investigated this outcome.

Can taking chloroquine in pregnancy cause learning or behavioural problems in the child?

A baby’s brain continues to develop right up until the end of pregnancy. It is therefore possible that taking certain medicines at any stage of pregnancy could have a lasting effect on a child’s learning or behaviour. 

A study of 251 one year old children who had been exposed to chloroquine in the womb showed that they were no more likely to have developmental problems than one year olds not exposed to chloroquine in the womb.

Because there are many aspects of learning and behaviour that have not yet been studied in relation to chloroquine exposure in the womb, much more research into this subject is required.

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.

Taking chloroquine during pregnancy is not expected to cause any problems that would require extra monitoring of your baby. However, if you have had malaria during your pregnancy your doctor may wish to monitor your pregnancy more closely.

Are there any risks to my baby if the father has taken chloroquine?

No studies have specifically investigated whether chloroquine used by the father can harm the baby through affects on the sperm, however most experts agree that this is very unlikely. More research on the effects of drug and medicine use in men around the time of conception is needed.

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  

How can I help to improve drug safety information for pregnant women in the future?

Our online reporting system (MyBump Portal) allows women who are currently pregnant to create a secure record of their pregnancy, collected through a series of questionnaires. You will be asked to enter information about your health, whether or not you take any medicines, your pregnancy outcome and your child's development. You can update your details at any time during pregnancy or afterwards. This information will help us better understand how medicines affect the health of pregnant women and their babies. Please visit the MyBump Portal to register.

General information
Sadly, miscarriage and birth defects can occur in any pregnancy.

Miscarriage occurs in about 1 in every 5 pregnancies, and 1 in every 40 babies are born with a birth defect. This is called the ‘background risk’ and happens whether medication is taken or not.

Most medicines cross the placenta and reach the baby. For many medications this is not a problem. However, some medicines can affect a baby’s growth and development.

If you take regular medication and are planning to conceive, you should discuss whether your medicine is safe to continue with your doctor/health care team before becoming pregnant. If you have an unplanned pregnancy while taking a medicine, you should tell your doctor as soon as possible.

If a new medicine is suggested for you during pregnancy, please make sure that the person prescribing it knows that you are pregnant. If you have any concerns about a medicine, you can check with your doctor, midwife or pharmacist.

Our Bumps information leaflets provide information about the effects of medicines in pregnancy so that you can decide, together with your healthcare provider, what is best for you and your baby.