(Date of issue: March 2016. 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?
Propranolol is a medicine that is prescribed to treat high blood pressure, angina, tremor, and anxiety. It is also used to prevent migraines. Propranolol belongs to a family of medicines called beta-blockers.
Is it safe to take propranolol in pregnancy?
There is no simple yes or no answer to this question. Propranolol use in pregnancy has not been shown to be harmful to a developing baby in the womb but more information still needs to be collected. When deciding whether to use propranolol during pregnancy it is important to weigh up how necessary propranolol 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 high blood pressure in pregnancy. Studies have shown that poorly controlled high blood pressure in pregnancy is linked to an increased chance of certain birth defects in the baby and stillbirth, as well as poor growth of the baby in the womb and premature birth. For some women who already had high blood pressure before becoming pregnant, continued treatment with propranolol in pregnancy might be considered to be the best option. Women with angina or other serious health conditions might also require treatment with propranolol during pregnancy. Your doctor is the best person to help you decide what is right for you and your baby.
What if I have already taken propranolol 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 propranolol 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.
Neither of two studies that investigated whether hypospadias (where the opening of the penis is on the underside rather than at the tip) in male babies might be linked to exposure to propranolol in the womb provided evidence of a link. A single study provided no evidence that use of propranolol in early pregnancy increases the risk of cleft lip and/or palate, or of neural tube defects (such as spina bifida) in the baby, although there were some problems with the way that the information in this study was collected and analysed. Because only a small number of studies have been carried out so far, more research into birth defect rates in babies exposed to propranolol in early pregnancy is required.
Can taking propranolol in pregnancy cause miscarriage?
A single study provided no evidence that use of propranolol in early pregnancy was linked to an increased risk of miscarriage. No further studies have assessed miscarriage rates in women taking propranolol and more research into this subject is therefore required.
Can taking propranolol in pregnancy cause stillbirth?
Poorly controlled high blood pressure in pregnancy is known to increase the risk of stillbirth. It is therefore complicated to work out whether medicines that are used to treat high blood pressure in pregnancy might also increase the risk of stillbirth.
A single study investigated the occurrence of stillbirth in a small number of women taking propranolol in pregnancy. Stillbirth occurred less commonly in these women when their high blood pressure was treated with propranolol. However, even with treatment, stillbirth was more likely amongst the women with high blood pressure than in the general population. This finding needs further investigation but does suggest that treatment with propranolol during pregnancy may reduce the likelihood of stillbirth in women with high blood pressure.
Can taking propranolol in pregnancy cause preterm birth?
Poorly controlled high blood pressure in pregnancy is known to increase the risk of preterm birth. It is therefore complicated to work out whether medicines that are used to treat high blood pressure in pregnancy themselves increase the risk of preterm birth.
Two very small studies have both provided no evidence that taking propranolol in pregnancy leads to the baby being born earlier. Because these studies were so small, more research is required before we can say whether use of propranolol in pregnancy increases the risk of preterm birth.
Can taking propranolol in pregnancy cause my baby to be small at birth (low birth weight)?
Poorly controlled high blood pressure in pregnancy is known to increase the risk of low birth weight in the baby. It is therefore complicated to work out whether medicines that are used to treat high blood pressure in pregnancy themselves increase the risk of low birth weight.
Two very small studies have produced opposite results regarding whether use of propranolol in pregnancy might be linked to reduced growth of the baby in the womb. More research is required to determine whether any observed effect is due to propranolol itself, the mother’s underlying illness, or a combination of the two.
Can taking propranolol in pregnancy cause other health problems in the baby/child?
Complications after birth
Beta-blockers can cause low heart rate, low blood sugar, and low blood pressure. Babies of women who used beta-blockers in the weeks before delivery might therefore experience these symptoms for a few hours or days after birth. There are some reports of these symptoms in newborn babies exposed to propranolol in the womb. If you have taken propranolol in the weeks before delivery your doctor or midwife might arrange for your baby to be born at a unit that can monitor and treat your baby, if necessary.
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. No studies have assessed whether propranolol use in pregnancy increases the risk of learning or behavioural problems in the child. This will ideally be the subject of future research.
Will I or my baby need extra monitoring during pregnancy or after delivery?
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 propranolol in pregnancy is not expected to cause problems that would require extra monitoring of your baby during pregnancy. However, women with high blood pressure, angina, and some of the other health conditions that propranolol is used to treat, will be more closely monitored to ensure that they remain well and their baby is growing and developing as expected.
Women with high blood pressure in pregnancy will be advised to monitor themselves for symptoms of pre-eclampsia. If you are experiencing symptoms of pre-eclampsia you should seek urgent medical help. Symptoms of pre-eclampsia include:
• Severe headaches that often do not get better after using pain relief.
• Visual problems, such as blurred vision, flashing lights, double vision or floating spots.
• Pain under the ribs, especially on the right hand side.
• Being sick.
• Feeling breathless.
• Sudden swelling of the face, hands or feet.
Babies born to women who used propranolol in late pregnancy might be closely monitored after birth to ensure that they are not experiencing adverse effects of beta-blocker exposure such as low heart rate, low blood sugar and low blood pressure. Babies experiencing these effects might require treatment and support for a few hours or days after delivery until the medicine has cleared from their system.
Are there any risks to my baby if the father has taken propranolol?
No studies have specifically investigated whether propranolol taken 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 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.