(Date of issue: June 2014. Version: 2)
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?
Loratadine (Clarityn®) belongs to a group of antihistamines called 2nd generation antihistamines that do not cause drowsiness. Loratadine is used to treat allergic symptoms.
Is it safe to take loratadine in pregnancy?
This leaflet summarises the scientific studies relating to the effects of loratadine on a baby in the womb. It is advisable to consider this information before taking loratadine if you are pregnant.
There is no strong evidence that loratadine is harmful to a baby in the womb. However, because only a relatively small number of women have been studied it is not possible to say for certain that it does not affect a baby in some way.
When deciding whether or not to take loratadine during pregnancy it is important to weigh up how necessary loratadine 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.
What if I have already taken loratadine during pregnancy?
If you have taken or are taking 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, if so, to make sure that you are taking the lowest dose that works and only for as long as you need to.
Can taking loratadine in pregnancy cause birth defects in the baby?
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 having a baby with a birth defect was seen in any of the three studies that investigated this risk in pregnant women taking loratadine. However, because fewer than 400 pregnancies where the mother took loratadine during the first trimester have been studied, further research is required to confirm these findings.
Some further studies have investigated whether there may be a link between using loratadine during early pregnancy and the baby having a specific malformation. The results are summarised below:
• One study suggested that baby boys born to women who had taken loratadine during early pregnancy were more likely to have hypospadias (where the opening on the penis is on the underside rather than the tip), but six other studies did not find this.
• Two studies both found no link between heart defects in babies and the mother using loratadine during early pregnancy.
• One study suggested that babies of women taking loratadine during early pregnancy had a higher chance of having a limb reduction defect (where the limbs are shortened or missing). No other studies have investigated any possible link between loratadine use in pregnancy and limb reduction defects and it is therefore not possible to say that there is a link based on only one study.
Taken together, the results of these studies do not provide firm evidence that taking loratadine during early pregnancy causes any of the defects listed above.
Can taking loratadine in pregnancy cause miscarriage?
There is currently no strong evidence that taking loratadine in early pregnancy increases the risk of miscarriage. Two studies have investigated this, with one study finding no increased risk of miscarriage in women taking loratadine. Although in the second study, women who took loratadine were about twice as likely to have a miscarriage as women who did not, it is thought that this could be explained by factors other than the loratadine. This is because in this study the group of women taking loratadine were, by chance, slightly older and were assessed at an earlier stage of pregnancy (when miscarriage is more likely) than women not taking loratadine and both of these factors could explain the higher rate of miscarriage. More research into this subject is required.
Can taking loratadine in pregnancy cause stillbirth, preterm birth, or my baby to be small at birth (low birth weight)?
No links between loratadine use in pregnancy and any of these pregnancy outcomes were found in either of the two studies that investigated them. However, only 350 women taking loratadine during pregnancy were studied in total and so further research is required to confirm these findings.
Can taking loratadine in pregnancy cause learning and 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.
There is no known link between taking loratadine in pregnancy and learning or behavioural problems (such as ADHD or autism spectrum disorder) in the child later on in life. There are, however, no scientific studies that have specifically investigated a link with these problems.
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. Taking loratadine in pregnancy would not normally require extra monitoring of your baby.
Are there any risks to my baby if the father has taken loratadine?
We would not expect any increased risk to your baby if the father took loratadine 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.