The risks of smoking while pregnant

Expecting a baby usually increases the pressure to stop smoking. We get that and we’re here to help you along your journey.

Quitting early on in pregnancy is best, but quitting at any time gives your baby a better chance of a healthy start in life. Here is what you need to know.

The risks of smoking while pregnant

• Miscarriage and ectopic pregnancy (the foetus is outside the womb)

• Complications during the birth

• Having a low-weight baby who is more vulnerable to infection and health problems in adulthood

• Pre-term delivery (birth at less than 37 weeks)

• The baby being born with a cleft lip or cross-eyes

• The baby being born with weaker lungs, which may persist into adulthood

• The baby having a weaker immune system

• The baby developing attention deficit hyperactive disorder (ADHD)

• The baby being overweight or obese in childhood.

In rare cases, the life of the baby may be endangered as smoking also increases the risk of Sudden Unexpected Death in Infancy (SUDI) and the risk of the baby dying at, or shortly after, birth. However, if you quit at any stage of your pregnancy there are health benefits for you and your baby.

If you quit before or during your first three months of pregnancy

• You reduce your risk of complications during the birth and have a better chance of a safe labour and birth for you and your baby.

• You lower the risk that your baby will be born too early (babies born early are more likely to have serious health problems than babies born at or near their due date).

• Your baby has the same chance of having a healthy birth weight as a baby of a non-smoker (babies who have a low birth weight as a result of smoking can have health problems because they are so small).

• You reduce the risk of your baby going through illness during their early years and, while rare, the risk of your baby dying at, or after, birth.

If you stop smoking later in your pregnancy

• Your baby has a better chance of having a healthy birth weight.

• It helps your baby practise their breathing movements to get ready for birth.

There are many benefits of quitting smoking for you and your baby. It might be challenging, but there’s a lot of support available.

Quitting early on in pregnancy is best, but quitting at any time gives your baby a better chance of a healthy start.

Does your smoking affect your unborn baby?

The umbilical cord is your baby’s lifeline. Blood flow through this cord provides your baby with oxygen and the food it needs to grow. Every puff you take on a cigarette has an immediate effect on your baby. Carbon monoxide replaces some of the oxygen in your blood, reducing the amount of oxygen received by your baby through the umbilical cord. Smoking also affects how the placenta forms, and reduces the nutrients crossing the placenta to your baby. Cigarette smoke also contains many other harmful poisons, which pass through your lungs and into your bloodstream (which your baby shares).

Download our Pregnancy and Smoking fact sheet for more information.