(Date of issue: July 2011. Version: 1.2)
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 cocaine?
Cocaine (coke, crack) is a recreational drug that causes changes in mood and behaviour by affecting the balance of certain chemicals in the brain.
Is it safe to use cocaine during pregnancy?
When a pregnant woman uses cocaine, it enters her bloodstream and crosses the placenta to the baby. Cocaine also collects in the fluid around the baby and is absorbed through the baby’s skin. Because unborn babies continually swallow this fluid they also swallow the cocaine. Cocaine in the baby’s bloodstream reaches the baby’s heart, brain, and other organs.
Studies suggest that using cocaine during pregnancy may increase the risk of stillbirth, or of having a premature and/or low birth weight baby. Cocaine should therefore not be used in pregnancy.
What if I have already used cocaine during pregnancy?
If you are pregnant and use cocaine, you should speak to your doctor or midwife about this. They will be able to get you help and support to safely stop using cocaine. Regular cocaine users, or people who feel as if they are dependent upon cocaine should not stop or reduce the amount of cocaine taken without a doctor’s guidance as this could cause withdrawal symptoms that may be dangerous to both mother and baby.
Can using cocaine during pregnancy cause birth defects?
Cocaine affects the blood vessels, reducing blood flow. There have therefore been concerns that use of cocaine in pregnancy may cause birth defects that are due to abnormal blood flow in the developing baby in the womb.
There are some isolated reports of babies with these types of birth defects being born to mothers who used cocaine during pregnancy.
One large study that analysed information from 16 smaller studies showed that babies born to women who used cocaine during pregnancy were more likely to have a birth defect than babies born to mothers who had not used drugs. However, birth defects were also more common in babies of women who had used other types of recreational drugs. This suggests that the birth defects observed in this study may not have been specifically caused by cocaine, but may have been caused by certain lifestyle factors in pregnant women who use recreational drugs (e.g. smoking, alcohol use, poor nutrition, ill health).
More research is required to determine whether cocaine use in pregnancy can cause birth defects in the baby.
Can using cocaine in pregnancy cause miscarriage?
Some studies have shown a link between cocaine use in pregnancy and an increased risk of miscarriage. However, other studies have not agreed with this and it is currently unclear whether using cocaine in pregnancy increases the chance of a miscarriage.
Can using cocaine in pregnancy cause stillbirth?
An increased risk of stillbirth has been linked to cocaine use in pregnancy. It has also been shown that placental abruption (where the placenta detaches from the womb before the baby is born) is more likely to occur in women who use cocaine whilst pregnant. Placental abruption can be very serious and can result in the death of both mother and baby.
Can using cocaine in pregnancy cause premature delivery and low birth weight?
Current scientific evidence suggests that cocaine use during pregnancy is linked to giving birth too early (<37 weeks of pregnancy) and to having a low birth weight baby (<2500g). Use of cocaine during pregnancy appears to reduce the rate at which a baby grows in the womb, possibly due to reduced blood flow through the placenta. Poor growth in the womb has been linked to health problems later on in life.
Can using cocaine in pregnancy cause other health problems in the child?
Withdrawal symptoms at birth (neonatal withdrawal)
Withdrawal symptoms are thought to occur as the newborn baby’s body has to adapt to no longer getting addictive substances through the placenta.
Studies have shown that cocaine use during pregnancy can cause withdrawal symptoms in the baby at birth. Therefore, if you have used cocaine in the weeks before delivery your baby may require close monitoring and/or supportive treatment for a few days after birth. It is important that you tell your doctor or midwife if you have been using cocaine so that they can arrange for your baby to be born at a unit that can monitor and treat your baby for withdrawal symptoms if necessary.
Growth in childhood
One study has shown that children who were exposed to cocaine in the womb during early pregnancy were smaller on average at seven and ten years of age than children who were not exposed to cocaine. This suggests that cocaine has lasting effects on a child who was exposed in the womb.
Learning or behavioural problems
A baby’s brain continues to develop right up until the end of pregnancy. It is therefore possible that exposure to certain substances at any stage of pregnancy could have a lasting effect on a child’s learning or behaviour.
Cocaine affects the balance of ‘mood chemicals’ in the brain. There are therefore concerns that using cocaine during pregnancy could also affect an unborn baby’s developing brain.
Several studies have shown that children whose mothers used cocaine during pregnancy were more likely to have problems with thinking, learning, and behaviour than children whose mothers did not use cocaine. One study has shown that the more cocaine that a mother used in pregnancy, the more likely a child was to have problems. However, other studies have not identified problems in children exposed to cocaine in the womb.
It is often difficult to compare different scientific studies of learning and behavioural problems in children who have been exposed to a particular substance in the womb. Studies often investigate different learning or behavioural issues, or use different scoring systems to identify a problem. The results can therefore not always be compared directly. Additionally, some studies only investigate children when they are young. We therefore do not know whether these children ‘grow out’ of any problems that are observed, or show more problems with their learning or behaviour as they get older.
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.
If you have used cocaine during pregnancy it is best for you and your baby that you tell your doctor or midwife as soon as possible. They will then be able to make sure that you and your baby receive extra monitoring or support if necessary.
Are there any risks to my baby if the father uses cocaine?
No studies have specifically investigated whether cocaine used by the father can harm the baby through affects on the sperm, however most experts agree that this is very unlikely. More research on the effects of drug and 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.