Being pregnant at diagnosis

Cancer in pregnancy is rare. Chemotherapy can usually be given after you are 14 weeks pregnant. It is not recommended before 14 weeks as it can harm the developing baby or cause a miscarriage.

You can sometimes delay having chemotherapy until your baby is born, although this isn’t always possible.

Your specialist will discuss all the options and help you come to a decision that is right for you.

Having chemotherapy during pregnancy

Research shows that giving certain chemotherapy drugs after 14 weeks will not harm the baby. Doctors will avoid giving any drugs that could be harmful.

In pregnancy the placenta is like a barrier between you and the baby. Some drugs can pass through the placenta and other drugs can’t.

At the moment research shows that after 14 weeks, children exposed to chemotherapy don’t have any more problems than those who aren’t exposed. The baby will have longer follow up to monitor their progress and check for any other possible risks.

Being monitored in pregnancy 

You'll have a team including cancer doctors, obstetricians and midwives looking after you and making a plan for your treatment. You might need more appointments with your obstetrician to see how you are feeling and to monitor the baby's progress. 

Your chemotherapy should stop 3-4 weeks before delivery. 

This is because chemotherapy increases the risk of:

  • infection during delivery
  • bleeding when giving birth

Risk of the baby being born early

Chemotherapy may increase the risk of having an earlier delivery. There is also evidence to suggest that your baby may have a lower birth weight.

Your team will check you closely and will plan for you to have your baby as close to your due date as possible.

Making decisions about your pregnancy

Sometimes you need to start chemotherapy quickly to control the cancer. In this situation your doctor may feel that it is best to end the pregnancy. In early pregnancy this might mean a termination. In later pregnancy it might mean delivering the baby early.

These are obviously very big decisions. You will need help and support to decide on the best thing for you to do. 

Talk to your doctor about your pregnancy. Make sure you completely understand all your choices and any risks before you make any decisions.

Last reviewed: 
03 Sep 2020
Next review due: 
03 Sep 2023
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  • Pregnancy and Breast Cancer

    Royal College of Obstetricians and Gynaecologists, 2011 

  • Cancer and its Mangement (7th edition)

    J Tobias and D Hochhouser

    Wiley Blackwell 2015

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    V T DeVita Jr., T S Lawrence and S A Rosenberg

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