Most children with childhood cancers survive, thanks to effective medical care. Some treatments cause few or no problems with reproductive health. Others, though, can greatly affect fertility.

But options like sperm banking or egg freezing, done before or after cancer treatment, can help many kids grow up to start families of their own.

How Can Cancer Treatment Affect Fertility?

Some cancer treatments can damage the testes or ovaries (reproductive organs). This can lead to temporary or permanent infertility (not being able to have children).

Chemotherapy, radiation, and surgery all can have lasting effects on reproductive health. A child's risk depends on their diagnosis, the type of treatment, and the dose of medicine.

In general:

Some chemotherapy drugs are more likely to affect reproductive organs than others. Some of the highest-risk drugs are cyclophosphamide (Cytoxan), lomustine, ifosfamide, procarbazine, busulfan, and melphalan. Others, like vincristine and methotrexate, are typically less likely to harm fertility. Some of these drugs also may interrupt menstruation in girls and/or cause early menopause (when periods stop completely).

Radiation treatments can damage testes or ovaries. Radiation focused on or near the pelvic area, abdomen, spine, and/or the whole body may damage sperm or eggs. Also, radiation to the abdomen, pelvic area, or entire body may affect how the uterus works and make it hard to carry a baby to full term. It also can interrupt menstruation in girls or reduce sperm count and motility (how sperm move) in boys. These problems may be permanent or can clear up after the treatment. Radiation to some areas of the brain also may affect fertility and the body’s ability to regulate hormones.

Surgery that involves the reproductive organs may affect how well those organs work in the future.

What Are the Options for Fertility Preservation?

Fertility preservation options can help many childhood cancer survivors start a family when they're ready.

If your child's treatment might affect their fertility, here are some options to consider.

Boys

For males who have gone through puberty: Sperm banking or "cryopreservation" is a common, non-invasive option. Sperm are collected and frozen for storage in a special facility. Some hospitals have sperm bank programs, or you might go to a clinic that specializes in sperm banking.

Another procedure called "sperm aspiration" might be possible. A small needle is inserted into the testes to collect sperm cells to use later for in vitro fertilization (IVF). IVF is when sperm fertilize an egg outside of the uterus, then the fertilized embryo is transferred to the uterus.

For boys and younger teens: An experimental option is available called testicular tissue cryopreservation. Doctors remove a small piece of testicular tissue and freeze it. Your doctor can help you decide if this is an option for your son.

Boys who have delays in puberty or growth due to chemotherapy and/or radiation should see an endocrinologist to talk about treatment options. If you have questions, be sure to ask your doctor.

Girls

Egg freezing requires mature eggs, so it only works for girls who have gone through puberty. They'll take medicines that help to grow the eggs in the ovaries. Then, doctors do a procedure to remove the eggs. The removed eggs are kept frozen. This method requires a period of ovarian stimulation, so it may not be an option for girls whose treatment must begin as soon as possible. If treatment can safely be delayed, egg freezing is the best way to preserve fertility. Later, these eggs can be fertilized with a partner's sperm or donor sperm to create embryos through IVF.

Ovarian tissue cryopreservation (before or after puberty) may also be an option, although not all hospitals can offer this procedure. With the patient under general anesthesia (asleep and not feeling pain), the surgeon removes one ovary and cuts it into strips, which are cryopreserved (frozen). The ovarian tissue can be reimplanted (put back into the body) later to restore function. Experts are also trying to figure out how to mature the tissue outside of the body without the need for reimplantation surgery. This would be a safer option for patients who are at a risk for the return of cancer cells from reimplanted tissue.

Depending on the type and target area of cancer treatment, doctors might be able to shield the ovaries from damage. They sometimes can do a surgery to reposition them, so they are away from the path of radiation (called transposition).

What Should I Ask the Doctor?

When thinking through these options, be sure to get all the facts from your care team. It can help to see a fertility specialist about which option (if any) would be best for your child.

Some questions to ask:

• Is this cancer treatment likely to damage my child's reproductive organs? If so, which areas may be affected and how will this affect fertility?
• What are the chances this treatment will cause my daughter to have early menopause? Can it affect some organs (like the lungs or heart) in a way that will make it hard for her to carry a pregnancy to term?
• Will this treatment have any effect on my son's reproductive health? If damage to sperm is likely, will the damage be temporary or permanent?
• Will this treatment have any effect on development during puberty?
• Are there ways to prevent infertility before we start treatment? Will any of these affect how well the cancer treatment works?
• What options, like sperm banking or egg preservation, are possible for my child? Are any experimental options available?
• After treatment, how will we know if my child's fertility has been affected?

If infertility is a possibility, it's important to know about other options for family planning in the future. These include adoption, sperm/egg donors, or use of a gestational carrier (surrogate). A gestational carrier carries the pregnancy for a woman who can't do so herself for health reasons or due to infertility.

How Can Parents Help?

As you explore the options, share as much as you can with your child. This might be hard. Sexuality and reproduction are often tough topics for parents and kids to discuss.

Even for young kids, the idea of infertility can bring complex emotions that are hard to process. Kids can have a deep sense of loss, or feel less feminine or masculine if faced with fertility problems. This is especially true for teens because sexuality and reproduction are important parts of their developing identity.

Here are some ways to help your child cope with these potential changes:

Talk about it. Keeping talks going with your child will help you plan for treatment and what comes afterward. Reassure them that they're not alone, and that many patients whose treatments put them at risk of infertility go on to have children. Others become parents through adoption, surrogacy, or other methods. Planning for the future can help your child stay positive and concentrate on getting well.

Keep hopes realistic. Be open and honest about the risk of infertility, the success rates of fertility preservation options, and any possible risks or complications. Be sure you and your child understand that nothing is guaranteed. Remind your child that they're still the same person, no matter what happens long-term. And, even if they can't physically conceive, they can still become a parent one day.

Get support. The care team is there for your family. Ask them about resources, like local support groups. The hospital or clinic may have a support group or counselor who can help your child work through the feelings that can come with cancer treatment and its effects. You also can find information and support online at:

• American Cancer Society
• Fertility Out Loud
• The Oncofertility Consortium