How cancer treatments can affect fertility in women
A lot of things must take place for a couple to make a baby, and a “system malfunction” at any point can lead to infertility. Cancer, or more often cancer treatments, can interfere with some part of the process and affect your ability to have children. Different types of treatments can have different effects.
- Targeted and biologic (immune) therapies
- Bone marrow or stem cell transplant
- Radiation therapy
- Other treatments
Most chemotherapy (chemo) drugs can damage a woman’s eggs and/or affect fertility. (Remember a woman is born with all the eggs she will ever have and they’re stored in her ovaries.) The effect will depend on the woman’s age, the types of drugs she gets, and the drug doses. This makes it hard to predict if a woman is likely to be fertile after chemo.
The chemo drugs most likely to cause egg damage and infertility are:
- Carmustine (BCNU)
- Cyclophosphamide (Cytoxan ®)
- Doxorubicin (Adriamycin®)
- Lomustine (CCNU)
On the other hand, the chemo drugs that have a low risk of damaging the eggs include:
- 5-fluorouracil (5-FU)
Talk to your doctor about the chemo drugs you will get and the fertility risks that come with them.
Chemo and pregnancy
Age makes a difference: Women who are treated for cancer before they are 35 have the best chance of becoming pregnant after treatment. Young women who stop having menstrual periods during treatment often start having periods again after they are off chemo for a while.
After chemo, fertility may not last as long: Girls who had chemo before puberty (the time when periods begin) or young women whose menstrual periods start back after chemo are at risk for early (premature) menopause. When a woman stops having periods long before the average age (about 51), it’s considered premature menopause. She becomes infertile because her ovaries stop releasing eggs. Early menopause also means that the ovaries stop making the female hormones estrogen and progesterone.
Periods don’t always mean fertility: Even if a woman’s periods start back after cancer treatment has stopped, her fertility is still uncertain. Usually some eggs are destroyed by cancer treatment. You may need a fertility expert to help you find out if you are fertile.
Avoid getting pregnant during chemo: Many chemo drugs can hurt a developing fetus, causing birth defects or other harm. You might be fertile during some types of chemo, so you’ll need to use very effective birth control. Talk with your doctor about this.
It can harm the baby if you get pregnant too soon after chemo: Women are often advised not to get pregnant within the first 6 months after chemo because the medicine may have damaged the eggs that were maturing during treatment. If a damaged egg is fertilized, the embryo could miscarry or develop into a baby with a genetic problem. Studies about this are hard to find. This is something you should talk to your doctor about before trying to become pregnant.
Targeted and immune therapies
Targeted drugs attack cancer cells differently from standard chemo drugs. Immunotherapy drugs help the body's own immune system attack cancer cells. Use of these types of medicines has increased a lot in recent years, but not much is known about their effects on fertility or problems during pregnancy. Still, some might cause problems.
An example is bevacizumab (Avastin®) – studies have found that this drug can cause ovarian failure, and some women’s ovaries never recover.
Another group of drugs that are of concern are targeted drugs called tyrosine kinase inhibitors (TKIs) such as imatinib (Gleevec®), which cause birth defects in lab animals. At this time the recommendation is that women talk to their doctors before becoming pregnant while taking TKIs.
It's very important to talk to your doctor about any targeted or immunotherapy drugs you will get and the fertility risks that might come with them.
Bone marrow or stem cell transplant
A bone marrow or stem cell transplant usually involves high doses of chemo and sometimes radiation to the whole body before the transplant. In most cases, this permanently stops a woman’s ovaries from releasing eggs. Talk with your doctor or nurse about this risk before starting treatment.
To learn more about transplants, see Stem Cell Transplant for Cancer.
Radiation treatments use high-energy rays to kill cancer cells. These rays can also damage a woman’s ovaries. For a woman getting radiation therapy to the abdomen (belly) or pelvis, the amount of radiation absorbed by the ovaries will determine if she becomes infertile. High doses can destroy some or all of the eggs in the ovaries and might cause infertility or early menopause.
Even if the radiation is not aimed right at the ovaries, the rays can bounce around inside the body and might still damage the ovaries.
When radiation is directed inside the vagina, the ovaries absorb a high dose of radiation.
Radiation to the uterus can cause scarring, which restricts flexibility and blood flow to the uterus. These problems can limit the growth and expansion of the uterus during pregnancy, and increase the risk of miscarriage, low-birth weight infants, and premature births.
Sometimes radiation to the brain affects the pituitary gland. The pituitary gland normally signals the ovaries to make hormones, so interfering with these signals can affect ovulation (the release of eggs from the ovaries). This might or might not affect fertility depending on the focus and dose of the radiation.
You may be fertile when you start getting radiation treatments, but it’s important not to become pregnant until treatment is completed because radiation can harm the fetus. Talk with your doctor about this.
Surgery on certain parts of the reproductive system can cause infertility. For some cancers, a hysterectomy is part of the treatment. A hysterectomy is surgery to remove the uterus (womb) either through the vagina or through a cut made in the abdomen (belly). Once the uterus is removed, a woman cannot carry a child.
The ovaries might be removed (called an oophorectomy) at the same time the uterus is taken out. Without ovaries, a woman can’t get pregnant because she no longer has any eggs. In some women with early stage ovarian or cervical cancer, the surgeon will try to save one ovary, if possible, to preserve eggs, which might still allow a woman to become pregnant. Keeping at least one ovary also preserves the hormones that prevent menopause symptoms like hot flashes and vaginal dryness.
Some women with small cervical cancers can have a surgery called a trachelectomy, which removes the cervix but leaves the uterus behind so a woman can carry a pregnancy. (See “Radical trachelectomy” in Preserving fertility in women with cancer.)
Sometimes surgery can cause scarring in the fallopian tubes. These scars may block the tubes and prevent eggs from traveling to meet the sperm. This means they can’t become fertilized and move on to the uterus to implant in the lining.
Hormone therapies used to treat breast cancer or other cancers can affect your ability to have a child. The effect of some other treatments on fertility and pregnancy is not yet known. It’s always best to talk to your doctor, nurse, or other member of your health care team about your treatment and any possible effects on your sexual function and fertility.
Last Medical Review: November 6, 2013 Last Revised: November 6, 2013
- Fertility and Women With Cancer
- Talking to your cancer care team about fertility before your treatment
- How cancer treatments can affect fertility in women
- Preserving fertility in women with cancer
- Preserving fertility in girls and teens with cancer
- Frequently asked questions
- Other fertility-related issues to think about
- To learn more