With more than 23,000 New Zealanders diagnosed with cancer each year, it also impacts many younger people who may be considering having children, so it’s important to understand how treatments for cancer may affect your fertility. We’ve outlined what you need to know in the guide below.
Cancer treatment and fertility: what you need to know
Does cancer treatment affect my fertility?
Whether you are male or female, if you are considering having children, we recommend you speak with your doctor before you begin any form of treatment.
Thankfully, fertility preservation methods such as embryo or egg freezing, ovarian tissue preservation and sperm freezing make it possible for men and women to preserve their fertility before starting cancer treatment.
Do I need to get a fertility referral?
If you would like to have children in the future, it’s important you talk through this with your doctor before starting treatment. Your doctor will be able to refer you to a fertility specialist so you can get all the information you need and any procedures before you start treatment.
A fertility specialist can answer any questions or concerns you have regarding bearing children in the future. They will advise you how best to preserve your fertility before commencing cancer treatment.
- I’d like to check my fertility levels before starting cancer treatment. Is this possible?
- Does my age affect my fertility? In what way?
- What will my chances of having children be after cancer treatment?
- What are the best ways to preserve my fertility before cancer treatment?
- Can you tell me what the fertility treatment process is and how it works?
- Are different fertility methods more effective than others in preserving my fertility?
Every female is born with the total amount of eggs that her ovaries will hold for her entire lifetime.
Before puberty, a female has approximately 400,000 eggs and her egg count has already decreased by puberty.
By the age of 30, women’s fertility decreases significantly, and by 40 years old, they have approximately 3% of their egg count. Egg quality also decreases.
Monthly, your ovaries release at minimum, one egg. Should a male’s sperm fertilise your egg, this egg becomes implanted into the womb. Should no fertilisation occur, you will have your period.
By menopause (approximately 51-years-old), the ovaries no longer release eggs. Women with the BRCA1 or BRCA2 gene mutations will likely experience the onset of menopause sooner. After menopause, you are not able to get pregnant naturally.
Unlike the female reproductive system, which has a finite number of eggs, the male reproductive system continuously produces, stores and transports sperm. Upon reaching puberty a man will produce millions of sperm each day.
Chemotherapy and fertility in women
The natural function of the ovaries is frequently affected by chemotherapy in pre-menopausal women. This can lead to a decrease in the quality and amount of eggs available, resulting in infertility.
Factors affecting future fertility include:
- Types of drugs used
- Dosage given
- Fertility level before breast cancer treatment
We encourage you to discuss all possible avenues to preserve and protect your fertility before you begin cancer treatment. This will help ensure you have the best possible chance to get pregnant in the future.
Effects of chemotherapy
There are many different treatment paths for cancer, which may also come with varied side effects. The main ones that impact your fertility are alkylating agents—compounds preventing cancer cells multiplying. This includes certain types of chemotherapy which are known to affect fertility.
Chemotherapy may cause your period to stop, either temporarily or permanently. For women under the age of 35, your period will likely resume. It is also not uncommon for your period to cease temporarily and commence after a few months or years post-cancer treatment, however this may not mean you are fertile.
Females who undergo cancer treatment tend to experience menopause anywhere from 5-10 years earlier, which means the window to get pregnant after cancer treatment is much smaller.
It’s important to speak with your doctor to discuss the best course of action to preserve your fertility before cancer treatment and maximise your chances of a successful future pregnancy.
Is pregnancy possible during hormone therapy?
Women diagnosed with oestrogen receptor-positive cancer (ER+) will often undergo hormone therapy.
Getting pregnant during hormone therapy for pre-menopausal women is possible. However, it is not advised during the entire course of this therapy. It is particularly harmful to an unborn baby’s development.
Certain types of cancer treatment, including testicular, prostate and bladder surgery, radiation therapy for testicular and prostate cancer, targeted therapy, immunotherapy, hormone therapy and chemotherapy, may impact your reproductive system and reduce your chances of having children. This will vary depending on your age, the type of treatment and the dose.
Men receiving targeted therapy or immunotherapy treatment are at higher risk of causing birth defects if they father a child during treatment.
Chemotherapy and fertility in men
If you receive certain types of chemotherapy as a child, this can damage your testicles and their ability to produce sperm. For men receiving chemotherapy treatment later in life, this may also affect your sperm production. Chemotherapy targets rapidly dividing cells to destroy cancer cells, however some healthy cells are also damaged including sperm. Following your chemotherapy treatment, your sperm production may slow or completely stop. Higher doses of certain chemotherapy drugs are more likely to impact your fertility permanently. Your doctor will be able to advise whether the chemotherapy treatment you will receive has a high risk of causing infertility.
There are a variety of fertility options available for preserving and protecting your fertility. These include embryo cryopreservation, egg (oocyte) cryopreservation and ovarian tissue preservation for women, and semen cryopreservation for men. Our team will be able to provide advice on next steps and refer you to a fertility specialist, if suitable.
Certain types of cancer treatment can be harmful to an unborn baby, so it is important to consider contraceptive options in addition to discussion with your doctor.
Men should consult with their doctor to explore non-hormonal contraceptive options, including condoms. For women, femidoms (female condoms) or a diaphragm are contraceptive options you may like to consider. In some instances, an IUD (intrauterine device) may also be suitable.