How Cancer and Cancer Treatment Can Affect Fertility in Females

It’s very important to talk to your cancer care team to know how a cancer surgery or treatment that's being recommended for you may affect your fertility before having the surgery or starting treatment. If these problems aren't talked about before surgery or treatment, it's important that they are brought up as soon as possible after surgery or when treatment starts. Don't assume your doctor or nurse will ask you about fertility concerns. Read more about talking with your health care team in How Cancer and Cancer Treatment Can Affect Fertility. You need to be sure to get enough information, support, or resources to help you deal with any doubts, feelings, and expected fertility problems. 

Fertility refers to having the ability to conceive, or being able to have a child. For females, fertility means they are able to become pregnant through normal sexual activity, and they are able to carry the baby through pregnancy. A person's fertility depends on their reproductive organs working properly and other factors, such as when and how often they are having sex, certain hormones, and if their partner has any problems with fertility.

When a person cannot have a child, this is called infertility, or being infertile. For females, infertility can mean they are not able to get pregnant through normal sexual activity or they have problems carrying a baby through pregnancy. Doctors usually consider someone to be infertile if they haven't been able to conceive a child after 12 or more months of regular sexual activity, or after 6 months if the female is more than 35 years old.

Problems with fertility can also be called reproductive problems or alterations. They happen when certain hormone levels are abnormally low or high or if sex organs are removed or aren't working properly. Some people never find out why they are having fertility problems. Many experts believe stress and anxiety can cause changes that play a part in infertility.

This information is for females with cancer. If you are a lesbian or a transgender person, please talk to your cancer care team about any needs that are not addressed here.

What can cause fertility problems

When a couple makes (conceives) a baby, this is called conception or reproduction. When a baby is conceived naturally, a lot of things must take place for it to happen. For example, we know a female is born with all the eggs she will ever have and they’re stored in her ovaries. Any change in how the ovaries work, or a change in a hormone that's needed to release an egg from the ovary during monthly cycles (called ovulation), can cause conception not to happen. In other words, there can be a “body system malfunction” that can change a woman's fertility and affect her ability to get pregnant and carry a child through a pregnancy. Certain health problems, including cancer, can affect these things.

Females can be diagnosed as infertile if:

• The ovaries don’t contain healthy eggs
• Hormones that are needed to help with egg release are disrupted
• A tumor or other problem might press on the ovaries or uterus (womb) and cause them not to work properly
• Damage to other parts of the reproductive system prevents eggs from being released, fertilized, or implanted
• A fertilized egg cannot grow inside the uterus
• Something happens that won't allow a fetus (unborn child) to be carried through the full pregnancy, causing a miscarriage

In many cases, cancer surgery or treatments can be more likely than cancer itself to interfere with some parts of the reproductive process and affect your ability to have children. Different types of surgeries and treatments can have different effects. The risk of infertility varies depending on:

• The patient’s age and stage of development; for example, before or after puberty, before or after menopause, etc.
• The type and extent of surgery
• The type of treatment given (radiation therapy, chemotherapy, hormone therapy, targeted therapy, immunotherapy, stem cell transplant)
• The dose of treatment

Surgery

Surgery might be needed for a tumor that's in or near another reproductive organ, such as an ovary or fallopian tube, or the uterus or cervix. It might also be needed for a tumor that's in nearby abdominal (belly) or pelvic organs, such as the colon, rectum, or anus. There are some tumors that happen near the nervous system, such as the brain or spinal cord. These surgeries may affect a woman’s fertility.

Surgery to remove reproductive organs

A hysterectomy is surgery to remove the uterus. Since an unborn child is carried in the uterus, once the uterus is removed, a woman cannot get pregnant. In females with cancer, removal of the uterus is done for uterine (endometrial) cancer, cervical cancer, and often for other cancers that affect the reproductive system.

An oophorectomy is surgery to remove the ovaries. It might be done at the same time as a hysterectomy. Since ovaries hold a woman's eggs, a woman can’t get pregnant without them. For females with cancer, an oophorectomy is done for ovarian cancer, and often for other cancers that affect the reproductive system. If possible, and if there is a low risk that the cancer will come back, the surgeon might try to save one ovary to preserve eggs, which might still allow a woman to become pregnant. Keeping at least one ovary also preserves the hormones that help prevent menopause symptoms like hot flashes and vaginal dryness. Some women at high risk for breast, uterine, and ovarian cancers choose to have an oophorectomy as a means to help prevent the cancers from starting.

A trachelectomy is surgery to remove the cervix (lower part of the uterus). It leaves the uterus behind so a woman has the chance to carry a pregnancy.

These surgeries can be done either through the vagina (laparoscopy) or through a cut (incision) made in the abdomen. You might hear people refer to a "partial" or "total" hysterectomy. This usually means the procedure only removes the uterus (partial) or it removes all reproductive organs (total).

Some women at high risk for breast, uterine, and ovarian cancers, or who have a hereditary cancer syndrome might choose to have a partial or total hysterectomy as a means to help prevent the cancers from starting.

Sometimes other types of cancer surgery that's done for tumors in the abdomen or pelvis can cause scarring in and around reproductive organs. These are called adhesions. They might block the ovaries, fallopian tubes, or uterus, preventing eggs from traveling to meet the sperm. This means the eggs can’t become fertilized and implant in the uterus.

Cancer Surgery gives you more information on surgery as a cancer treatment.

Radiation therapy

Radiation treatments use high-energy rays to kill cancer cells. Radiation that's aimed at or around a woman’s reproductive organs can affect fertility.

Radiation to the pelvis area

Radiation that's aimed at or around the ovaries damages them enough to affect their function. Even if the radiation is not aimed right at the ovaries, the rays can be absorbed and might still damage the ovaries. When radiation is directed inside the vagina, the ovaries absorb a high dose of radiation.

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. Most women getting pelvic radiation will lose their fertility. But, some eggs might survive if the ovaries are moved further from the target area in a minor surgery to preserve them that might be able to be done before radiation begins.

Radiation to the uterus can cause scarring, which decreases flexibility and blood flow to the uterus. It also makes the uterus unable to stretch to full size during pregnancy. These problems can limit the growth and expansion of the uterus during pregnancy. Women who have had radiation to the uterus have an increased risk of miscarriage, low-birth weight infants, and premature births. These problems are most likely in women who had radiation during childhood, before the uterus began to grow during puberty.

Radiation to the brain

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.

Some females may be fertile when starting radiation treatments. If you are fertile or you think you might be, it’s important to talk to your doctor about your risk for infertility before treatment starts.

Radiation can harm a fetus. So, if you are fertile and your fertility might not be affected by radiation treatments, it's also important to talk about how long you should wait to resume unprotected sexual activity or to try for a pregnancy. Your doctor will be able to consider your circumstances and give you specific information about how long you should wait to try to get pregnant.

You can get more details about this type of treatment in Radiation Therapy.

Chemotherapy

A female is born with all the eggs she will have. As she moves through puberty, hormones allow mature eggs to be released every month during the menstrual cycle until the female reaches menopause and the hormonal cycles eventually stop.  Chemotherapy (chemo) works by killing cells in the body that are dividing quickly. The hormones, such as estrogen, needed to release eggs each month and prepare the uterus for a possible pregnancy are made in the cells of the ovaries (oocytes). Oocytes tend to divide quickly, so are often affected by chemo. This can lead to loss of those important hormones and can affect fertility. Sometimes a woman will go into premature or early menopause.

Fertility depends on the female’s stage in life (before or after puberty, before or after menopause), menstrual history, hormone levels, the type of cancer and treatment, and the treatment doses. Because all these factors need to be considered, it can be hard to predict if a woman is likely to be fertile after chemo.

Chemo drugs that are linked to the risk of infertility in females are:

• Busulfan
• Carboplatin
• Carmustine
• Chlorambucil
• Cisplatin
• Cyclophosphamide
• Cytosine arabinoside
• Doxorubicin
• Ifosfamide
• Lomustine
• Melphalan
• Mitomycin-C
• Nitrogen mustard (mechlorethamine)
• Procarbazine
• Temozolomide
• Thiotepa
• Vinblastine
• Vincristine

Higher doses of these drugs are more likely to cause permanent fertility changes, and combinations of drugs can have greater effects. The risks of permanent infertility are even higher when females are treated with both chemo and radiation therapy to the belly (abdomen) or pelvis.

Some other chemo drugs that have a lower risk of causing infertility in females include:

• 5-fluorouracil (5-FU)
• 6-mercaptopurine (6-MP)
• Bleomycin
• Cytarabine
• Dactinomycin
• Daunorubicin
• Epirubicin
• Etoposide (VP-16)
• Fludarabine
• Gemcitabine
• Idarubicin
• Methotrexate

Talk to your doctor about the chemo drugs you will get and the fertility risks that come with them. 

Chemo and pregnancy

There are things that cause a female to have a higher risk for infertility, and others that might not affect fertility at all. Here are some examples:

• Age makes a difference. The younger you are, the more eggs you usually have in your ovaries. This gives you a higher chance to keep some fertility in spite of damage from treatments. Women who are treated for cancer before they are 35 have the best chance of becoming pregnant after treatment. Depending on the treatment they are getting, some women in their teens or twenties never stop having periods until they reach menopause. Young women who stop having menstrual periods during treatment may have a return of periods again after they are off chemo for a while.
• Puberty and menopause make a difference. After chemo, fertility may not last as long as it would if treatment wasn't needed. 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 before age 40, it’s considered premature ovarian failure or primary ovarian insufficiency.  She becomes infertile because her ovaries stop making the hormones needed for fertility. Of course, females who have had surgery to remove reproductive organs cannot get pregnant.
• Having periods doesn’t always mean a female is fertile. Even if a woman’s periods start back after cancer treatment has stopped, her fertility is still uncertain. A fertility expert might be needed to help find out if you are fertile or learn how long the fertility window may last.

If you are fertile or think you might be fertile, it's very important to avoid getting pregnant during chemo. Many chemo drugs can hurt a developing fetus, causing birth defects or other harm. Some can contribute to having a miscarriage. Some women remain fertile during chemo, so it's best to use very effective birth control.  Remember, too, that some women can get pregnant even when their periods have stopped. For this reason, it’s important to use birth control whether or not you have periods, but talk to your cancer care team about what's best for your situation.

If you remain fertile through treatment and want to get pregnant after it ends, be sure you know how long you should wait before trying. Studies about this are hard to find, but some suggest getting pregnant too soon after chemo can harm the fetus, cause birth defects, or cause a woman to miscarry

See Chemotherapy for more information.

Hormone therapy

Hormone therapies are often used to treat breast cancer or other cancers. These can affect your ability to have a child. Some of these drugs, such as tamoxifen, might not cause problems getting pregnant, but can cause birth defects. Other hormone therapies may block or suppress hormones, causing infertility by putting a woman into early menopause. This may be temporary or permanent, depending on the type and length of treatment.

It’s always best to talk to your cancer care team about your treatment and any possible effects on your sexual function and fertility. It's also very important to talk about whether you need to use birth control during and after treatment.

Targeted therapy and immunotherapy

Targeted therapy and immunotherapy drugs attack cancer cells differently from standard chemo drugs. Little is known about their effects on fertility or problems during pregnancy. 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, and any precautions that might be needed. Some information is known, such as:

• Bevacizumab (Avastin^®) can cause ovarian failure, and some women’s ovaries never recover.
• Some targeted drugs (thalidomide and lenalidomide) have such a high danger of causing birth defects that women are asked to use two effective types of birth control while taking them.
• Tyrosine kinase inhibitors (TKIs) have caused birth defects in lab animals.

See Targeted Therapy and Immunotherapy to learn more about these cancer treatments.

Bone marrow or stem cell transplant

Having a bone marrow or stem cell transplant usually involves receiving high doses of chemo and sometimes radiation to the whole body before the procedure. In most cases, this permanently stops ovaries from releasing eggs, resulting in lifelong infertility. Talk with your doctor or nurse about this risk before starting treatment. (See Chemotherapy and Radiation Therapy for more on these parts of the transplant process.) If you'd like to learn more, see Stem Cell Transplant.