(Date: February 2016. Version: 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 the UK Health Security Agency (UKHSA) 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 it?

Chloramphenicol is an antibiotic that is most commonly used in the form of eye drops to treat eye infections and can be bought over-the-counter for this purpose. It is also occasionally prescribed in the form of ear drops to treat ear infections, and may be used in hospital to treat life-threatening infections, where it is generally given intravenously (via a vein).

Is it safe to use chloramphenicol in pregnancy?

There is no yes or no answer to this question. When deciding whether to use chloramphenicol during pregnancy it is important to weigh up how necessary chloramphenicol is to your health against any possible risks to you or your baby, some of which might depend on how many weeks pregnant you are.

It is important to appropriately treat infections in pregnancy. For some women with serious infections, treatment with chloramphenicol in pregnancy might be the best option. Your doctor is the best person to help you decide what is right for you and your baby.

The amount of chloramphenicol that enters the bloodstream (and therefore reaches the baby) following use of chloramphenicol eye drops, as instructed, is not expected to cause harm to a baby in the womb. However, as use in pregnancy has not been fully studied, pregnant women using chloramphenicol eye drops may wish to reduce the amount of chloramphenicol reaching the bloodstream by applying pressure with their finger at the inner corner of the eye for one minute or more after applying the drops, or gently closing the eyelids for one or two minutes after use.

What if I have already used chloramphenicol during pregnancy?

If you have taken or used any medicines it is always a good idea to let your doctor know that you are pregnant so that you can decide together whether you still need the medicines that you are on and to make sure that you are taking the lowest dose that works.

Can using chloramphenicol 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.

Two studies that together include over 6,000 babies born to women who used chloramphenicol eye drops in early pregnancy have provided no strong evidence that their use increases the risk of the baby having a birth defect.

No studies have investigated whether birth defects are more common in babies of women who were treated with intravenous chloramphenicol.

Can using chloramphenicol in pregnancy cause miscarriage or stillbirth?

No studies have investigated whether rates of miscarriage or stillbirth are increased in women who use chloramphenicol in pregnancy.

Can using chloramphenicol in pregnancy cause preterm birth or my baby to be small at birth (low birth weight)?

No studies have investigated whether rates of preterm birth or low birth weight in the baby are increased following use of chloramphenicol in pregnancy.

Can taking chloramphenicol in pregnancy cause other health problems in the baby/child?

Grey baby syndrome
Grey baby syndrome is a serious adverse reaction (side effect) that has been observed in some newborn babies (especially those who are premature) who were given chloramphenicol after birth. Grey baby syndrome results from too much chloramphenicol accumulating in the baby’s body, either because the baby was given very high doses or because the baby’s liver and kidneys were not mature enough to clear the chloramphenicol from the body. There have been worries that babies exposed to chloramphenicol in the womb just before delivery might also be at risk of Grey baby syndrome. Although there are no reliable reports of this happening, as a precautionary measure, some doctors still prefer to avoid use of chloramphenicol in pregnant women around the time that the baby is due.

A possible link between asthma in children of women who used of chloramphenicol in pregnancy was investigated in a single study. This study found that a diagnosis of asthma after the age of seven years was more common not only in children who were exposed to chloramphenicol in the womb in the first trimester of pregnancy, but also in those who were exposed to another unrelated antibiotic. More studies are required to determine whether a true link between treatment with chloramphenicol or other antibiotics in pregnancy and childhood asthma exists, or whether other factors about the health or lifestyle of mothers who needed to take antibiotics in pregnancy may explain why their children are more likely to have asthma.

Learning and behavioural problems
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.

There is currently no indication of a link between chloramphenicol use in pregnancy and learning and behavioural problems in children. However, no scientific studies have been carried out to investigate this and are therefore required to rule out any effects.

Will my baby need extra monitoring?

Most women will be offered a scan at around 20 weeks of pregnancy to look for birth defects as part of their routine antenatal care. Using chloramphenicol in pregnancy is not expected to cause problems that would require extra monitoring of your baby. However, women who have had a serious infection during pregnancy might be more closely monitored to ensure that their baby is growing and developing as expected.

Are there any risks to my baby if the father has used chloramphenicol?

No studies have specifically investigated whether chloramphenicol used by the father can harm the baby through effects on the sperm, however most experts agree that this is very unlikely. More research on the effects of 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

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General information 

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.

Disclaimer: This information is not intended to replace the individual care and advice of your health care provider. New information is continually becoming available. Whilst every effort will be made to ensure that this information is accurate and up to date at the time of publication, we cannot cover every eventuality and the information providers cannot be held responsible for any adverse outcomes following decisions made on the basis of this information. We strongly advise that printouts should NOT be kept for any length of time, or for “future reference” as they can rapidly become out of date.

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