Background

Breast cancer and my fertility

Your breast cancer treatments may decrease the number and quality of eggs in your ovaries. This means you may find it harder or you may be unable to get pregnant after treatment. Your risk of infertility after treatment depends on a number of factors. The most important factors include:

your age at diagnosis
your age when you plan to get pregnant
the type and dose of cancer treatment

How does age affect my fertility?

You have a fixed number of eggs in your ovaries when you are born.
As you get older, the number and quality of eggs decreases. This means that as you age your chances of becoming pregnant naturally also go down.
Your fertility declines 10 to 13 years before menopause. This is called the perimenopausal period.
Eventually you will have few to no eggs left in your ovaries. This is called reaching natural menopause. You can no longer get pregnant after you reach menopause.
It is important to note that natural pregnancy ends before menopause. This means even before you reach menopause, you are unlikely to achieve natural pregnancy for many years before that.

Graph: Natural decline in the number of your eggs as you age. — The graph below shows that as you age normally, the number of eggs in your ovaries go down until you reach menopause.

How will cancer treatment affect my fertility?

The chart below shows the treatments you may have and how they affect fertility. You should not try to get pregnant while on any treatment for your breast cancer.

Treatment	Will this treatment affect my fertility?
Breast Surgery	No – Unless you have surgery to take out your ovaries. Removal of your ovaries will affect your fertility.
Breast Radiation	No – Unless you have radiation to your ovaries. Radiation to your ovaries will affect your fertility.
Chemotherapy	Possibly – Cyclophosphamide is one drug that can affect your fertility the most. It is usually given in combination with other chemotherapy drugs.
Hormone (Endocrine) Therapy	Possibly – If your cancer is hormone sensitive, you may be taking hormone therapy for 5 or more years. This will delay your ability to get pregnant, as you should not try to get pregnant during this treatment.
Trastuzumab (Herceptin^®)	Unknown – If you have HER2+ breast cancer, you will be on Herceptin for about 1 year. This will delay your ability to get pregnant, as you should not try to get pregnant during this treatment.

What can happen to my fertility during chemotherapy?

Some chemotherapy drugs reduce the number of eggs in your ovaries. This can cause you to go into menopause after treatment or earlier than normal. This is called premature ovarian insufficiency (POI).

During chemotherapy, you may stop getting your periods. You may experience menopausal symptoms.
After chemotherapy, your periods may start again in a few months or it may take up to a year for them to come back.
Your period coming back depends on your age and how many eggs were in your ovaries before treatment. It also depends on the type and total dose of chemotherapy given.
If you do not have your period during or after chemotherapy it does not always mean you are in permanent menopause. You may still be able to get pregnant at this time.
Even if your period comes back after chemotherapy, you may not be able to have a natural pregnancy. This is due to the lower number and quality of eggs in your ovaries.

Use the LIVESTRONG Fertility Risk Tool to learn more about your risk of your periods stopping based on the chemotherapy drugs you may receive.

What can happen to my fertility during hormone (endocrine) therapy?

Hormone therapy does not affect your fertility. However, if you have hormone therapy for 5 or more years your fertility will decrease as you age.
You may be able to interrupt hormone therapy before the full treatment is completed, while you try to become pregnant. Then you could continue hormone therapy after your child is born. The effect of this is still being studied. Talk with your oncologist about taking a break from treatment in order to try to get pregnant.

How will I know if I am still able to get pregnant after I finish chemotherapy and hormone therapy?

Your fertility specialist can do tests to help determine how many eggs are left in your ovaries. The tests may show you have:

Normal fertility

You have enough good quality eggs left in your ovaries to have a natural pregnancy. This is assuming that you and your partner have no other fertility problems.
Your ability to have a natural pregnancy will vary by your age. If you are younger in age, you have a higher chance of having a natural pregnancy after treatment. This is because you had more eggs and better quality eggs in your ovaries before starting treatment.

Premature ovarian insufficiency (POI)

Your ovaries stop working early. Your ovaries may not produce normal levels of estrogen or release eggs regularly.
You may still be able to have a natural pregnancy after treatment but you will begin menopause earlier in your life. It may also take longer or be harder for you to become pregnant.

Permanent menopause

Your periods do not start again and you have few to no eggs in your ovaries.
Permanent menopause after treatment is likely if you are over the age of 45 when you are diagnosed. This is because you are closer to natural menopause at the time you started treatment. The average age of menopause in Canada is 52 years of age.
You will not be able to have a natural pregnancy after menopause.

FAQs

I am not ready to have a child. Why should I consider my fertility now?: Even if you are not ready to have a child now you may find it useful to think about your fertility. You may get treatment for 5 or more years to prevent your cancer from coming back. You should not get pregnant while on treatment. During this time on treatment your fertility will go down. You should think about the age you will be when you are done treatment when making your fertility decisions.

Do I need to take birth control when I am receiving cancer treatment?: Your doctor may advise you to use birth control to prevent a pregnancy during treatment. You would choose a form of birth control that does not change your hormones, such as condoms or non-hormonal intrauterine devices (IUD).