How cancer treatments can affect fertility in men

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.

  • Chemotherapy
  • Targeted and immune therapies
  • Hormone therapy
  • Bone marrow or stem cell transplant
  • Radiation therapy
  • Surgery


During puberty (usually around age 13 to 14), a boy’s testicles start making sperm, and they normally will keep doing so for the rest of his life.

Chemotherapy (chemo) works by killing cells in the body that are dividing quickly. Since sperm cells divide quickly, they are an easy target for damage by chemo. Permanent infertility can result if all the spermatogonial stem cells (the immature cells in the testicles that divide to make new sperm) are damaged to the point that they can no longer produce maturing sperm cells.

The risk of the chemo causing infertility varies depending on:

  • The patient’s age. For example, men older than 40 may be less likely to recover their fertility after treatment.
  • The type of drug(s) used. Some drugs are more likely to affect fertility than others (see lists below).
  • The doses of drugs given. The higher the doses of chemo, the longer it takes for sperm production to get back to normal after treatment, and the more likely it is to stop.

After chemo treatment, sperm production slows down or may stop altogether. Some sperm production usually returns in 1 to 4 years, but it can take up to 10 years. If sperm production has not recovered within 4 years, it’s less likely to ever recover.

Chemo drugs that are linked to the highest risk of infertility in men include:

  • Actinomycin D
  • Busulfan
  • Carboplatin
  • Carmustine
  • Chlorambucil
  • Cisplatin
  • Cyclophosphamide (Cytoxan®)
  • Cytarabine
  • Ifosfamide
  • Lomustine
  • Melphalan
  • Nitrogen mustard (mechlorethamine)
  • Procarbazine

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

Some drugs, such as those listed here, have a low risk of causing infertility in men, as long as they are given in low to moderate doses:

  • 5-fluorouracil (5-FU)
  • 6-Mercaptopurine (6-MP)
  • Bleomycin
  • Cytarabine (Cytosar®)
  • Dacarbazine
  • Daunorubicin (Daunomycin®)
  • Doxorubicin (Adriamycin®)
  • Epirubicin
  • Etoposide (VP-16)
  • Fludarabine
  • Methotrexate
  • Mitoxantrone
  • Thioguanine (6-TG)
  • Thiotepa
  • Vinblastine (Velban®)
  • Vincristine (Oncovin®)

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

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. These types of drugs have been used a lot more in recent years, but not much is known about their effects on fertility or problems during pregnancy.

The small amount of data that’s available on a group of targeted drugs called tyrosine kinase inhibitors (TKIs), such as imatinib (Gleevec®), suggests that pregnancies started by young men getting TKIs are probably not at an increased risk of complications or birth defects. Still, these men need to know that there’s not enough research available to know that it’s safe to start a pregnancy while on these drugs. And at this time the recommendation is that men talk to their doctor before starting a pregnancy 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. 

Hormone therapy

Some hormone therapies used to treat prostate or other cancers can affect sperm production and your ability to have a child. Talk to your doctor about this risk and about whether it’s safe to start a pregnancy while taking these drugs.

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 causes life-long infertility – it permanently prevents a man from making sperm.

To learn more about transplant, see Stem Cell Transplant for Cancer.

Radiation therapy

Radiation treatments use high-energy rays to kill cancer cells. Radiation to a man’s testicles can affect his fertility. Radiation at high doses kills the stem cells that produce sperm.

Radiation is aimed directly at the testicles to treat some types of testicular cancer and childhood leukemia. Young men with seminoma, a type of cancer of the testicle, may have radiation to the groin area, very close to their remaining testicle. Even when a man gets radiation to treat a tumor in his abdomen (belly) or pelvis, his testicles may still end up getting enough radiation to harm sperm production.

Sometimes radiation to the brain affects the pituitary gland. The pituitary gland normally signals the testicles to make hormones, so interfering with these signals can affect sperm production and cause problems with fertility.

You may be fertile when you’re getting radiation treatments, but your sperm may be damaged so it’s important to not start a pregnancy until treatment is completed. Talk to your doctor about how long you should wait.

For men getting radiation for prostate cancer

Brachytherapy: Seed implants for prostate cancer do not give a large dose of radiation to the testicles, and most men will remain fertile or recover sperm production. These men will need to use birth control during and after treatment if they do not want to father a child.

External radiation: Radiation for prostate cancer from a machine outside the body is more likely to cause permanent infertility, even if the testicles are shielded.


Surgery offers the greatest chance of cure for many types of cancer, especially those that have not spread to other parts of the body. But surgery on certain parts of the reproductive system can cause infertility.

The following types of surgery may affect a man’s fertility:

Surgery for testicular cancer

The surgical removal of a testicle is called an orchiectomy. This is a common treatment for testicular cancer. As long as a man has one healthy testicle, he can continue to make sperm after surgery. (Less than 5% of men develop cancer in both testicles.) But some men with testicular cancer have poor fertility because the remaining testicle is not truly normal.

Testicle removal (both testicles) for prostate cancer

Some men with prostate cancer that has spread beyond the nearby area may have both testicles removed to stop testosterone production and slow the growth of prostate cancer cells. This is called a bilateral orchiectomy. These men cannot father children unless they banked sperm before surgery.

Surgery to remove the prostate (radical prostatectomy)

For men who have prostate cancer that has not spread beyond the gland, surgery to remove the prostate gland and seminal vesicles is one of the treatment options. The prostate and seminal vesicles are the parts that produce semen. Whether the prostate is removed through a cut in the abdomen (belly) or in the perineum (the area behind the testicles and in front of the anus), this surgery leaves men with no semen. Surgery to remove the prostate also can damage the nerves that allow a man to get an erection, causing erectile dysfunction (ED). This means he cannot get an erection sufficient for sexual penetration.

Even if you can get an erection, if there’s no semen coming from the penis during orgasm, you cannot conceive a child during sex. But there are ways to remove sperm and use it to fertilize an egg

Surgery to remove the bladder (cystectomy)

Surgery to treat some bladder cancers is much like a radical prostatectomy, except the bladder is also removed along with the prostate and seminal vesicles. The testicles still make sperm, but the vas deferens (the paths the sperm take to the urinary tube) are cut. With sexual stimulation, men can still have the feeling of orgasm, but no fluid comes out of the penis and the sperm cannot get out. 

Because no semen comes out of the penis during orgasm, you cannot conceive a child during sex. But there are ways that sperm might be taken out and used to fertilize an egg.

Surgery that interferes with erection and ejaculation

A few types of cancer surgery can damage nerves that are needed to get an erection and ejaculate semen. They include removing lymph nodes in the pelvis, which may be part of the surgery for testicular cancer and some colon cancers. Nerves are often damaged when removing lymph nodes, and this can cause problems with erections and ejaculation. Sometimes surgery can completely paralyze the prostate and seminal vesicles, which normally squeeze and relax to move the semen as a man’s climax begins.

After these operations, a man still makes semen, but it doesn’t come out of the penis at orgasm (climax). Instead it either shoots backward into his bladder (called retrograde ejaculation) or does not go anywhere.

In cases of retrograde ejaculation, medicines can sometimes restore normal ejaculation of semen. The seminal vesicles contract, the internal valve at the bladder entrance closes, and semen is ejaculated from the penis at orgasm. In the United States, ephedrine sulfate is the most common medicine used to restore normal ejaculation. Because it does not help everyone and may only work for a few doses, ephedrine sulfate is usually prescribed only for the fertile week of the woman’s cycle.

Fertility specialists can also gather sperm from these men using several types of treatments including electrical stimulation of ejaculation or sperm aspiration surgery (described in Preserving Fertility in Men with Cancer).

The American Cancer Society medical and editorial content team
Our team is made up of doctors and master’s-prepared nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Last Medical Review: November 6, 2013 Last Revised: February 9, 2017

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