After your multidisciplinary team (MDT) have had a meeting, your doctor and nurse will explain the treatment options to you. You will probably want your partner, if you have one, family or a close friend to be with you.

You and your doctors and nurses will need to talk things over carefully. As far as possible, doctors try to give the same treatment as they give women who are not pregnant. Sometimes certain treatments may need to be delayed because they are not safe for the baby.

You need to fully understand the risks and benefits of your treatment options before you decide. This may involve having several appointments with your cancer team. Your doctors and nurses know you will need time to think about and understand the information they give you.

You may be making hard decisions that affect your own life and your pregnancy. You may also have other children to think about. You will need lots of support from your partner, if you have one, family, close friends and your doctors and nurses.

Unless you have a fast-growing cancer, you will not usually need to make a decision straightaway. You can usually take time to think about how you are feeling and which options feel right for you. Your doctors and nurses will give you advice and can help you make your decision. It may also help to see a psychologist or counsellor to talk things over.

Decisions about ending the pregnancy

Women can usually have effective treatment while pregnant. So most of the time it is not necessary to end the pregnancy.

However, in certain situations, your cancer specialist may advise you to end the pregnancy. This is usually only when there is a serious risk to your health. For example, if the pregnancy is early and the cancer is fast-growing and needs urgent treatment that would not be safe for the baby. Or it could be if you need an operation that cannot be done during pregnancy. It depends on the type of cancer, its stage and how far along the pregnancy is.

Ending a pregnancy does not improve the outlook (prognosis) for a cancer. But it may mean you can have the most effective treatment without doctors needing to change it to protect the baby. Your cancer doctor and nurse will explain things carefully to you. They will help you understand the risks to your health of continuing with the pregnancy.

Having to think about ending a pregnancy is very distressing. It is a deeply personal decision that only you can make.

Some women may have been planning their pregnancy for a long time or struggled to become pregnant. It may even be the result of going through fertility treatment.

You will need a lot of support from your partner, if you have one and close family and friends. Your healthcare team will also support you and respect the choices you make.

You may have strong protective feelings towards the developing baby. For some women, ending a pregnancy may not be acceptable.

You may decide for yourself to have a termination even if your specialist is not suggesting that you have one. This may be because you feel you cannot get on with having treatment and recovering while being pregnant. Or you may want to focus on getting well for the family you already have. Whatever the reasons, it is very upsetting to have to make the decision.

It is natural to need extra support from an expert counsellor or a psychologist. They will have experience in supporting people going through a loss.

Your doctors will look at a number of things before advising you about the best treatment options. These are:

• how many weeks pregnant you are
• the type of cancer and its stage
• how slowly or quickly the cancer is growing
• if the aim of treatment is to cure the cancer or to control it.

How many weeks pregnant you are

How far along you are in your pregnancy is important when deciding about treatment. It affects the timing of different treatments, particularly chemotherapy.

A pregnancy usually lasts for about 40 weeks. It is divided into periods of around three months called trimesters. During each trimester, the baby goes through different stages of development.

First trimester is week 0 to 13 (month 0 to 3)

The baby is developing and its organs and limbs are forming. Because of this, doctors usually avoid giving chemotherapy. Some types of surgery may be delayed until later.

Second trimester is week 14 to 27 (month 4 to 6)

The baby is growing quickly and the lungs and other vital organs are developing. You can have chemotherapy any time from 14 weeks onwards. You can also have some operations.

At 24 weeks pregnant, the baby has a chance of survival if he or she is born.

Third trimester is week 28 onwards (month 7 to 9)

This is the final stage of growth when the baby moves into position for birth.

If you are diagnosed in the third trimester, it may be possible to delay treatment until after the baby is born. This depends on the type of cancer you have (see below). Or, you may have treatment to control the cancer until the baby is born. You can then start the main treatment. Another option may be for your baby to be delivered early if the neonatal doctors (experts in the care of new-born babies) think the baby can cope with this. This means you can start cancer treatment earlier.

The type of cancer

Doctors try to give the same treatment as they would give to a woman with the same cancer who is not pregnant. In some situations, treatment may need to be changed or delayed to protect the baby. Your doctor will talk all this over with you before you make decisions about your pregnancy and treatment.

It is also important to consider the stage of the cancer and if it is slow-growing or fast-growing.

Slow-growing cancers

With some slow-growing cancers, doctors may be able to monitor them during pregnancy (see information on monitoring below). If the cancer starts to grow, they usually advise that you start treatment.

If the cancer is diagnosed later in pregnancy, your doctor may advise delaying treatment. You can start it after the baby is born.

Fast-growing cancers

If the cancer is growing quickly, doctors usually advise you to start treatment straightaway.

If your pregnancy is early, they usually talk to you about ending the pregnancy. This is because the cancer is a serious risk to your health. They can then give you the best possible treatment for your situation. You will be given lots of support to help you to cope with this distressing situation.

If the cancer is diagnosed in the third trimester, doctors may advise an early delivery. This is usually if you have a certain type of leukaemia or lymphoma. You will start intensive chemotherapy straight after the baby is born.

Fertility

You may still have concerns about possible effects of treatment on your fertility, even though you are pregnant. If this is a concern for you, talk to your doctor before treatment starts. Certain ways of preserving fertility will not be possible during pregnancy. But there may be other things they can think about, such as the type of chemotherapy drugs you have.

We have more information on cancer treatment and fertility that you might find helpful.

With very early-stage or slow-growing cancers, doctors may suggest checking (monitoring) the cancer while you continue with the pregnancy. After the baby is born you can start treatment. Your specialist may suggest this if the cancer is not likely to change much during the rest of your pregnancy. It depends on the type of cancer you have and how many weeks pregnant you are.

It is often easier to decide to monitor the cancer when you are further along in pregnancy. In early pregnancy, it may be too long a time to monitor the cancer until the baby is born.

Monitoring may be an option if you have:

• low-grade lymphoma
• stage 1 cancer of the cervix
• another low-grade cancer, such as some brain tumours.

If monitoring is an option, your doctor and nurse will talk it over with you. They will explain the type of checks you will have. This will depend on the type of cancer you have.