Other late effects after an allogeneic blood and marrow transplant

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Learn about late term effects after your child's blood and marrow transplant (BMT).

Key points

  • Other late effects after and allogeneic BMT can have an impact on fertility, the risk of developing secondary cancers, the thyroid, the heart, dental, respiratory problems, cataracts, learning and memory.

After your child's blood and marrow transplant (BMT), they may be at risk of developing other types of late effects. Keep in mind that these are the potential late effects and not necessarily what your child will develop. Many BMT survivors go on to lead healthy and productive lives. Being aware of possible late effects will help you look for early signs and get the best treatment right away.


When your child enters adulthood, they may start to think about having children. The high-dose chemotherapy and total body irradiation (TBI) that your child receives before the BMT may affect your child’s fertility. Some children may have problems reproducing when older. If your child is diagnosed around the age of puberty (age 11 or 12) or later, you and your child may want to consider banking his sperm.

Discuss these options with your child’s doctor if you or your child has any questions or concerns.

Secondary cancers

Another potential risk after receiving an allogenic transplant is developing secondary cancers.

While preparing for the transplant, your child received high-dose chemotherapy. They may also have received radiation to the entire body, called total body irradiation (TBI). These treatments help kill any diseased cells and make space in your child's marrow for the new stem cells. However, they may also damage the DNA inside healthy cells, causing secondary cancers.

Regular follow-up after treatment is important so that your child's doctor can check for any early signs of these cancers.


If your child receives radiation therapy, they may later develop problems in the thyroid, which is a butterfly-shaped organ at the bottom of our neck (just below the Adam’s apple in males). Our thyroid gland excretes hormones which regulate our body weight, heart rate, and how we use energy.

Radiation can interrupt this process, causing the thyroid to produce fewer hormones than it normally does. This condition is called hypothyroidism. If left untreated, hypothyroidism can cause weight gain, fatigue, and other health problems.

Your child’s doctor will check for signs of hypothyroidism during follow-up visits. The condition is easy to treat. If your child develops the hypothyroidism, the doctor will prescribe a synthetic thyroid hormone, which is safe and effective.


As part of your child’s treatment, they may take a chemotherapy medicine called cyclophosphamide. They may also receive TBI. Both these treatments could damage the heart, making it hard for the heart muscle to pump properly. Eventually, the heart just cannot keep up and your child can develop symptoms like fatigue or breathing problems.

During treatment, doctors will adjust the dose of cyclophosphamide to try to minimize the effects on the heart. However, it is still important for your child to see a doctor often and have a heart ultrasound (echocardiogram) regularly.


Side effects from the conditioning regimen can also dental problems. Children who receive a transplant before the age of five are particularly vulnerable to developing issues with their teeth. These problems may include:

  • loose teeth
  • tooth loss
  • dry mouth
  • incapable of wearing braces

It is important that a dentist checks your child’s teeth routinely, after the transplant. Some dentists are experienced in treating children who have received high-dose chemotherapy or TBI.

Respiratory problems

Conditioning therapy as well as graft-versus-host disease (GVHD) can damage the lungs. For most children, the effects are minor and they have no problem participating in activities as other children. Although some children may experience respiratory problems, such as shortness of breath or cough.

Diagnosing respiratory problems early can help minimize the chances of your child developing problems with their lungs. It is important for your child to have their lungs checked every two years. This is done using a test that measures the strengths of the lungs, in a test called pulmonary function test.


TBI and prolonged use of steroids may also cause clouding in the lens of the eye, interfering with eyesight. This is called cataracts. It can develop gradually over several years.

Like many other potential late effects of treatment, identifying signs of cataracts in the early stages is key to prevention. It is important for your child to see an eye specialist, at least once every two years.

Learning and memory

Learning and memory skills depend on the ability of our brain to process information and apply knowledge. This ability is called neurocognition. It includes our language, memory, concentration, and capacity to grasp new concepts. These are skills we apply in education, on the playground, and in the workplace.

In general, BMT childhood survivors go on to lead healthy and normal lives without experiencing any cognitive difficulties. However, some children experience mild to moderate learning challenges, such as problems with memory or motor skills. Creating an encouraging family and school environment for your child, can greatly influence how well your child does in the long run. The sooner you understand the potential late effects, the better prepared you will be to help your child access effective resources so they can get appropriate support in school. Set up a meeting with a neuropsychologist. They can help to identify learning and memory problems. They can also suggest useful support groups and appropriate ways you can help your child.

Last updated: April 7th 2010