Fertility in women means being able to get pregnant and give birth to a baby.
The parts of your body that allow you to do this include your ovaries, fallopian tubes, womb (uterus), cervix and vagina. This is called your reproductive system.
The pituitary gland at the base of your brain is also important for fertility. It releases hormones (chemical messengers) that control how your reproductive system works.
Fertility in women depends on having:
- a supply of eggs from the ovaries
- a healthy womb (uterus)
- suitable hormone levels.
To become pregnant, a woman’s egg needs to be fertilised by a man’s sperm. Normally once a month, from puberty to menopause, one of the ovaries releases an egg.
This process is controlled by hormones produced by the pituitary gland and by the ovaries. The ovaries make the main female hormones oestrogen and progesterone.
The egg moves along the fallopian tube where it can be fertilised by a sperm. The fertilised egg develops into an embryo. The embryo continues to the womb where it can bury itself into the womb lining and grow into a baby. Hormones prepare the lining of the womb for the embryo. If the egg is not fertilised, you have a period.
You are born with a large number of eggs and as you get older, the number and quality of your eggs decreases. When there are very few left, you go through the menopause.
Some cancer treatments can affect the ovaries or the pituitary gland and cause an early menopause. Others can cause a temporary menopause or menopausal symptoms.
Doctors may not be able to predict exactly how your fertility will be affected. But your age and the planned treatment can help give an idea of your individual risk. Sometimes it may be possible to reduce the effects of treatment on your fertility
Treatments can damage or affect:
- the eggs in the ovaries
- the pituitary gland and hormone production
- the womb, cervix or ovaries.
Cancer and cancer treatment can also change how you feel about sex or make it physically difficult to have sex. We have more information about coping with sexual difficulties that may be useful.
Which cancer treatments can affect fertility?
The main treatments for cancer are chemotherapy, radiotherapy, surgery, hormonal therapy and targeted therapy. These can affect your fertility in different ways:
Chemotherapy reduces the number of eggs stored in your ovaries and can mean fewer or no eggs are released. Your periods may become irregular or stop for a while. It may take up to 2 years for them to come back again.
Sometimes chemotherapy causes permanent infertility and an early menopause. The older you are and the closer you are to your natural menopause, the higher the risk of infertility.
It may be possible to choose a chemotherapy treatment that is less likely to affect your fertility. Or some women may be given a type of hormone therapy during chemotherapy to try to protect the ovaries. Your cancer doctor can explain if these are options for you.
Radiotherapy treats cancer by using high-energy rays to destroy cancer cells. It only affects the area of the body being treated. It can cause fertility problems by:
- affecting the eggs
- damaging the ovaries, womb or pituitary gland
- reducing hormones (oestrogen and progesterone).
Types of radiotherapy which may affect fertility include:
- radiotherapy to the pelvis
- total body irradiation (TBI) is radiotherapy given to the whole body before a donor stem cell or bone marrow transplant – this usually causes permanent infertility
- radiotherapy to the brain
- radioactive iodine.
Radiotherapy to other areas of the body will not cause infertility.
Hormonal therapies can slow down or stop cancer cells growing. Hormonal therapy can affect your fertility but this is usually temporary. The drugs most commonly used are goserelin (Zoladex®) and tamoxifen.
Your periods may change or stop while you are taking these drugs. But it is still important to use contraception to prevent a pregnancy. Most women will get menopausal side effects such as hot flushes while taking goserelin or tamoxifen.
Some women go through their natural menopause during treatment. If this happens, you may not be aware of it because the side effects of the drugs are similar to the symptoms of the menopause.
Targeted therapies are a newer type of cancer treatment. It is not yet known exactly what effect they have on fertility. If you are treated with a targeted therapy, your cancer doctor can tell you about possible risks to your fertility.
Contraception during cancer treatment
It is important to use contraception during cancer treatment and for a time after it. Cancer treatments may harm a developing baby. Even if your periods stop during treatment you might still be able to get pregnant. Your cancer doctor will tell you how long you need to use contraception for.
It is difficult to predict when fertility will recover. This could happen without you being aware of it. If you do not want to have a child, you should keep using contraception unless doctors tell you that your infertility is permanent.
If you have breast cancer, your doctor may advise you not to use contraception that contains hormones, such as the contraceptive pill. This is because the hormones could encourage breast cancer cells to grow. Your cancer doctor or specialist nurse will give you more advice about this.
It is important to talk to your cancer doctor or nurse about fertility before you start cancer treatment. Some women are referred to a fertility expert before starting cancer treatment. This is to discuss ways of increasing their chances of getting pregnant in the future (fertility preservation). This is not always possible. For example, there may not be enough time if cancer treatment has to start immediately.
Questions you could ask your medical team
- How will my fertility be affected?
- Are there ways to protect my fertility during cancer treatment?
- Can I store embryos, eggs or ovarian tissue?
- What type of contraception should I use during cancer treatment?
- What fertility treatments will help in my situation?
You may be referred to a fertility clinic for advice before starting cancer treatment. This will depend on your age and type of cancer.
The doctors at the fertility clinic will explain treatments that may save (preserve) your fertility and help you get pregnant in the future. They will give you information about any risks of fertility treatments. They will also tell you how likely the treatments are to result in pregnancy.
This can be a lot of information to take in. You may want to take notes or have some questions ready to ask the doctor. You may be offered counselling or further support to help.
Fertility preservation usually involves stimulating your ovaries with drugs to release more eggs than normal (ovarian stimulation). These eggs are then collected and frozen. This means that the eggs can be fertilised in the future using a partner’s sperm or donor sperm.
Some religions may not agree with certain fertility treatments. If this is an issue for you, you may want to discuss it with your partner, family or religious adviser. You can also talk in confidence with a trained counsellor or social worker.
Before your eggs are collected, you may have injections under the skin of gonadotrophin hormones. This makes your ovaries produce more mature eggs than usual. It is called ovarian stimulation and takes at least two weeks.
Ovarian stimulation is not suitable for everyone. There may not be time for this if you need to start cancer treatment straight away.
For some women there are risks with the drugs used to stimulate the ovaries. These drugs increase the levels of the hormone oestrogen. Doctors are concerned that oestrogen may encourage some cancers to grow. This includes some types of breast, ovarian and endometrial (womb) cancer. Eggs may still be collected:
- without using drugs to stimulate the ovaries. One or two eggs may be collected in this way. But having fewer eggs reduces the chances of getting pregnant in the future.
- with one treatment of ovarian stimulation in the usual way.
- using a hormonal drug called letrozole during ovarian stimulation. Letrozole helps protect you from the effects of oestrogen on cancer cells.
Your doctor will explain any risks of ovarian stimulation and give you information about your options.
After ovarian stimulation, you will have blood tests and ultrasound scans. An ultrasound uses sound waves to make an image of your ovaries. This is to check how the follicles which contain the eggs are developing in the ovaries.
When the follicles have developed enough, the doctor uses an ultrasound inside the vagina to guide a needle into the ovaries and collect the mature unfertilised eggs.
The ultrasound probe is about the size of a tampon. The collection takes about 15 to 20 minutes. This can be uncomfortable so you will be sedated while it is done. You can usually go home a few hours after. Collecting as many eggs as possible increases your chances of a pregnancy in the future.
The eggs can be frozen and stored after they have been collected. There are different ways to do this. However, the most successful way to freeze eggs is a technique called vitrification. This involves freezing the eggs very quickly. This is not available at every fertility clinic. Talk to your fertility doctor about your options.
This is another common and effective way of preserving fertility. After your eggs have been collected, they are placed in a sterile dish with sperm to encourage fertilisation. This is called in vitro fertilisation (IVF). The eggs that are fertilised grow into embryos, which are frozen and then stored.
Vitrification of embryos results in higher pregnancy rates than slow freezing. But both are safe procedures and many babies have been born using these techniques.
At present, freezing embryos is more likely to result in a pregnancy than freezing eggs. But success rates for freezing eggs are improving.
If you have a partner who has provided sperm for this, he has equal rights in deciding what happens to the embryos in the future. If he withdraws the right for you to use the embryos, you will not be able to use them.
Even if you have a partner who can provide sperm, you can still choose to have unfertilised eggs frozen. Your partner has no say in how those eggs are used in the future.
Storing embryos and eggs
The NHS often provides embryo and egg storage for women with cancer. But in some areas of the UK you may have to pay for it yourself. The staff at the fertility clinic will explain what’s available in your area.
Embryos and eggs can be stored for at least 10 years and for longer in some situations. They will be frozen and stored in a tank of liquid nitrogen. This is called cryopreservation.
Freezing tissue from an ovary
Before cancer treatment starts, doctors remove an ovary or small pieces of your ovary by keyhole surgery. These are frozen and stored. These pieces of ovary contain thousands of immature eggs. After cancer treatment, if you decide to try for a baby, the pieces of ovary can be put back into your body. This can make it possible to conceive naturally or with IVF treatment.
This technique is suitable for most women. It is especially suitable for those who have to start cancer treatment quickly, those who can’t have fertility drugs, or girls who haven’t reached puberty. It may not be suitable if there might be cancer cells within the ovary.
This is a newer technique and it is not widely available in the UK. Only a few babies in the world have been born using this method.
Worrying about your fertility may seem especially hard when you are already coping with cancer. You may find it helps to talk things over with your partner, family or friends. If you prefer to talk to a counsellor, your GP or cancer doctor can help to arrange this. Many hospitals also have specialist nurses who can offer support, and fertility clinics will have a counsellor you can talk to.
Talking to other women in a similar position may help you feel less isolated. Macmillan’s Online Community is a good place to start. You can also talk things over with our cancer support specialists free on 0808 808 00 00.