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Substance misuse in pregnancy

If you are pregnant and using illegal or prescribed medication, you should seek advice from your GP or Midwife as soon as possible. 

Due to the risks involved in taking drugs during pregnancy, we advise all pregnant women to avoid any drugs unless prescribed by a medical practitioner. Find out more information about safe medication in pregnancy. 

What to do if you become pregnant and you’re using drugs?

The first trimester (up to 12 weeks) is a crucial period in your baby’s development and it is important that you seek antenatal care as soon as you find out that you’re pregnant.

Whether you’re using illegal drugs or prescribed medication, you should tell your GP or Midwife so they can help you to access the right help and support. 

Effects of substance misuse in pregnancy

Drugs can have harmful effects on the embryo or foetus at any stage of pregnancy. 

In the first trimester some drugs can affect the development of the foetal organs and in severe cases may cause miscarriage.

In the second trimester (13 to 28 weeks) some drugs may reduce the baby’s growth, resulting in low birth weight which may have a lasting impact once born on their learning, behaviour and developmental skills which could cause future childhood illnesses.

In the third trimester (final three months), continuing to use drugs may cause a premature birth and in some cases withdrawal of the baby.

Withdrawal of the baby from drugs

Babies are not born dependant even if the mother is but they can suffer distressing withdrawal symptoms due to dependence from what the mother has been taking in pregnancy.

Some babies may show signs of withdrawal within the first 72 hours of being born and in some circumstances may continue for 14 days depending on drugs used in pregnancy. The signs may be uncoordinated sucking, vomiting and diarrhoea and poor weight gain and in rare cases, convulsions may occur. Babies will be monitored and treated as required whilst in hospital and the mothers would be supported by professionals during this period as well.

Some effects may not be obvious at birth but can become evident later in their life.

The risks of substance misuse in pregnancy

Substance misuse during pregnancy increases the risk of:

  • Having a premature or low weight baby.
  • The baby suffering symptoms of withdrawal from drugs used by mother during pregnancy.
  • The death of the baby before or shortly after birth.
  • Sudden Infant Death Syndrome.
  • Physical and neurological damage to the baby before birth, particularly if violence accompanies. parental use of drugs or alcohol.
  • Pregnant women drinking to excess risk delivering babies with Foetal Alcohol Syndrome. Find out more information about the risks of drinking alcohol in pregnancy.

Useful links and resources

Confidential help and support is available: