(Date of issue: August 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 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 it?
Tetracycline is an antibiotic that is prescribed to treat many different types of bacterial infection. Tetracycline is also used to treat acne.
Is it safe to take tetracycline in pregnancy?
Tetracycline is not often used during pregnancy, particularly in the second or third trimesters, as use during this period is known to cause a baby’s milk teeth to be permanently stained and discoloured when they come through after birth. Occasionally however it may be necessary to use tetracycline to treat an infection (e.g. if no other antibiotic is likely to clear the infection fully). Effective treatment of infections during pregnancy is crucial to the health of both mother and baby.
When deciding whether or not to take tetracycline during pregnancy it is important to weigh up how necessary tetracycline is to your health against the possible risks to you or your baby, some of which will depend on how many weeks pregnant you are. Your doctor is the best person to help you decide what is right for you and your baby.
This leaflet summarises the scientific studies relating to the effects of tetracycline on a baby in the womb.
What if I have already taken tetracycline during pregnancy?
If you have taken 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 taking tetracycline 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.
No increased risk of birth defects in general has been shown in any of four studies of children exposed to tetracycline in the womb.
A small number of studies have investigated possible links between taking tetracycline in the first trimester and specific birth defects. Because only small numbers of women taking tetracycline have been studied, more research is needed to confirm these findings. The studies are detailed below:
• Two studies of pregnant women taking tetracycline investigated a possible link with cleft lip and/or palate in the baby. The findings did not agree, with one study finding a possible link, and the other finding no link. However, because of problems with the way that the information was collected and/or analysed in both of these studies, further research is required before we can say whether or not there is a link.
• One study identified a possible link between tetracycline use in pregnancy and a heart defect called transposition of the great arteries (TGA) (where the blood vessels in the baby’s heart are connected incorrectly). No other studies have looked specifically at whether TGA is linked to tetracycline use in pregnancy and it is therefore not possible to say whether there is a link based on only one study.
These studies do not provide strong scientific evidence that taking tetracycline in pregnancy increases the chance of birth defects in the baby. However, more information on pregnant women taking tetracycline needs to be collected.
What problems can taking tetracycline in the second or third trimesters cause in my baby?
Discolouration of the teeth
It is well known that use of tetracycline during the second or third trimesters of pregnancy can discolour the unborn baby’s developing milk teeth and prevent the enamel from forming properly. This means that when the baby’s milk teeth come through they might be stained grey, brown or yellow. The baby’s second set of ‘permanent teeth’ will be unaffected.
Effects on bone growth
Tetracycline taken in pregnancy accumulates in the developing baby’s bones and there are concerns that this may affect a baby’s bone growth. Although there are one or two reports of babies exposed to tetracycline in the womb being born with bone problems, it is not clear whether the tetracycline definitely caused them. It has been shown that tetracycline given to newborn babies temporarily alters their bone growth, but that this returns to normal once the tetracycline is stopped. Until more pregnant women taking tetracycline are studied, we cannot say whether tetracycline use during pregnancy is likely to have long-term effects on a baby’s bone growth.
Can taking tetracycline in pregnancy cause miscarriage, stillbirth, preterm birth, or my baby to be small at birth (low birth weight)?
No links between tetracycline use in pregnancy and any of the above pregnancy outcomes are known about, however no scientific studies have been carried out that have specifically investigated this and more research is therefore required.
Can taking tetracycline 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.
No link with learning and behavioural problems (e.g. autism spectrum disorder [ASD] and attention deficit hyperactivity disorder [ADHD]) is known about in children who were exposed to tetracycline while in the womb, however no studies have been carried out to specifically investigate this.
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.
There is no evidence that taking tetracycline during pregnancy causes any problems that would require extra monitoring of your baby.
Are there any risks to my baby if the father has taken tetracycline?
We would not expect any increased risk to your baby if the father took tetracycline before or around the time you became pregnant.
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.