Silicone breast implants

Date: May 2017, Version 1.1

What are silicone implants?

Silicone breast implants are used for surgical breast enlargement and breast reconstruction. Silicone implants usually consist of a shell of silicone gum filled with a softer silicone gel or, less commonly, a saline (salt) solution. Breast implants generally have a limited lifespan and may need to be replaced after 10-15 years. There is a risk that the silicone filler may leak into the body if the implant ruptures. It has been estimated that up to six in every 100 silicone implants will rupture.  

In 2010, a particular brand of silicone implants (made by the French company Poly Implant Prosthèse [PIP]) was discontinued in the UK after they were found not to contain medical-grade silicone. Around 47,000 women in the UK had received PIP implants. PIP implants were shown to rupture more often than other types of implant. Despite this, there is no evidence that PIP implants can specifically cause serious health problems.

Do silicone implants pose a risk during pregnancy?

The information in this leaflet summarises the available scientific studies of pregnancies in women with silicone implants. These studies do not suggest that silicone implants cause harm to a baby in the womb. It should, however, be noted that not all possible effects on a pregnancy have been studied. There is also no published information specifically relating to pregnancies in women with PIP implants.

Can silicone implants 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 and other substances can potentially cause birth defects.

Two large studies together investigated a total of over 2,300 babies born to women with silicone implants. Both concluded that birth defects were no more common in these babies than in babies born to women without silicone implants.

Can silicone implants cause miscarriage?

No studies have investigated whether pregnant women with silicone implants are more likely to have a miscarriage than women without implants.

Can silicone implants cause stillbirth?

No large studies have specifically investigated whether stillbirth is more common in women with silicone implants. However, two studies of a total of over 2,000 pregnant women with silicone implants both concluded that the risk of perinatal death (death of the baby just before or just after delivery) was not increased in babies born to women with silicone implants.

Can silicone implants cause preterm birth or my baby to be small at birth (low birth weight)?

Probably not. Only one study of 423 pregnant women with silicone implants has investigated these outcomes. Preterm birth, or the baby being smaller than expected for the delivery date, were no more likely among the women with implants than the women in the study without silicone implants.

Can silicone implants 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.

No large studies have investigated learning and behaviour in children born to mothers with silicone implants.

Can silicone implants have any other effects on the child’s health?

There have been a number of individual case reports of auto-immune diseases in non-pregnant women with silicone implants, some of which have been reported in the media. However, a very large analysis of 2,600 papers on this subject concluded that there is no increased risk of auto-immune illness in people with silicone implants.

Because of the interest in this subject, children born to women with silicone implants in place during pregnancy have also been studied to see whether they are more likely to develop specific auto-immune illnesses than children born to women without implants. Two large studies that together investigated a total of over 2,300 children born to women with silicone implants both concluded that they were not more likely to develop these illnesses. Two small studies which measured the levels of molecules in the blood that are used to diagnose and monitor auto-immune illnesses showed that levels of these molecules were not abnormal in children born to mothers with silicone implants.

Will my baby need extra monitoring during pregnancy?

As part of their routine antenatal care, most women will be offered scan and blood tests from around 11 weeks of pregnancy and a further scan at around 20 weeks to look for birth defects in the baby. Having silicone implants is not expected to cause problems that would require extra monitoring of your baby.

Is it safe to breastfeed with silicone implants?

Several small studies have assessed the health of babies who were breastfed by women with silicone implants. There is no evidence that the presence of silicone implants during breastfeeding increases the risk of auto-immune illness or stomach problems in the baby. An additional small study that measured the quantity of silicone in breast milk from women with implants found that levels were not increased compared to women without implants. Furthermore, silicone levels in infant formula and cow’s milk were at least 10 times higher than in breast milk from women with implants.

Breast implants can in some cases affect the production of breast milk. Women with implants who are concerned about this should speak to their doctor or midwife.

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.