Stem cell transplant factsheet


A stem cell transplant is also called a bone marrow transplant. It can be used to treat certain types of cancer, such as leukemia and lymphoma, and other blood and immune system diseases that affect the bone marrow (soft spongy tissue found in the centre of most bones).

The stem cells needed for transplant can be either sourced from the patient (called an autologous transplant) or from another person (called an allogeneic transplant). 

 Preparing for treatment

Before the transplant, you will travel to the clinic where you are receiving treatment. You will talk with a transplant specialist and your child will have a medical examination and different tests. 

Your doctor will recommend the best transplant option for you. Your options depend on the specific disease diagnosed, how healthy your bone marrow is, your age, and your general health.

A transplant will require a lot of time receiving medical care away from your daily life. 

During the treatment

The transplant process usually follows the below steps:

Collecting stem cells

This step takes several days. First, you will get injections of a medication to increase your stem cells. Then your health care team collects the stem cells through a vein in your arm or your chest (or from your donor). The cells will be stored until they are needed. 

You will get chemotherapy, with or without radiation therapy, to prepare your body to receive the cells. 

This step usually takes 5-10 days. 

Stem cells for transplant can be collected from:

  • the bone marrow (in which case the transplant will be called a bone marrow transplant),  
  • blood circulating in the bloodstream (a peripheral blood stem cell transplant)  
  • the umbilical cord of a newborn baby (a cord blood transplant).  

Conditioning therapy

Conditioning therapy must be given to prepare your child for transplant. This involves intensive chemotherapy and sometimes radiotherapy.

There are three aims of the conditioning therapy:

  • eradicate remaining cancer cells through high dose chemotherapy or radiotherapy
  • so the transplanted stem cells are not rejected, the immune system is suppressed 
  • to give new stem cells a place to grow, the bone marrow cells are destroyed.

The transplant can go ahead 24 hours after conditioning therapy has finished.


Whatever transplant type your child is being given (bone marrow, cord blood, peripheral blood) the stem cells they receive will be infused through the central line. This procedure is straightforward and does not usually cause a reaction.  

If the stem cells are from a matched sibling, there is no need to freeze them. Once collected from the sibling in the operating theatre, they will be infused into your child in the same way as a blood transfusion. 

If the stem cells have been frozen, they will be thawed in the transplant room, drawn up into a syringe and either injected into the central line or infused like a blood transfusion, depending on the volume of cells.

A chemical preservative called DMSO is used to protect the stem cells during the freezing process. The DMSO has a strong odour, which you will notice on your child’s breath once the stem cells have been infused. This usually lasts for about 24 hours. 


Transplanted stem cells circulate in the blood for some hours before moving to the bone marrow cavity in a process referred to as ‘homing.’  

Depending on the type of stem cells given, it can take on average 2-3 weeks for the stem cells to start producing new blood cells.

Neutrophils (a type of white blood cell) are the first cell to be produced and when these cell counts start to rise, it is a sign that the new marrow is engrafting (coming together).

Until the new marrow is producing enough blood cells to meet demand in the body, your child will need regular blood and platelet transfusions. 

 After the treatment

Recovery from a bone marrow/stem cell transplant takes a long time. Recovery starts as intensive medical monitoring after your transplant day and transitions to a schedule of regular medical checkups.  

It is common to develop an infection after a bone marrow transplant, even if you are very careful. Follow your health care team's recommendations for how to prevent infection immediately after your transplant. 

You will have regular blood tests and other tests to see how your body is responding to the treatment.  

 More information

Autologous transplants

Autologous transplants (transplants using the child’s own stem cells) are undertaken for the treatment of some solid tumours such as neuroblastoma and brain tumours.  

If your child needs an autologous transplant, their stem cells will be collected, frozen and then given back via an intravenous infusion after high dose chemotherapy or radiotherapy.

The timing of transplant varies according to the disease. In some settings it may be done once the disease is under control and in other settings, it may only be done if the disease relapses. 

Allogeneic transplants

Allogeneic transplants are the treatment of choice for all other diseases and situations. If your child needs an allogeneic transplant, the best stem cell donor they can have is a histocompatible (matched) sibling.

There is a 25% chance that any two siblings will be a match. If there is no matched sibling donor available, the national and international donor registries will be searched to identify a matched unrelated donor. 

Transplant complications

There are four main complications following transplant: 

  1. Rejection: the new marrow may not engraft or may be rejected
  2. Veno-occlusive disease: this is a unique type of liver impairment seen after transplant, usually within the first 20 days
  3. Graft-versus-host-disease: the immune cells contained in the transplant recognise the patient as ‘foreign’ and attack organs of the body including the skin, gut and liver. 
  4. Infection: because the immune system is so suppressed during the transplant and for a period after transplant, there is a high risk of infection including bacterial, viral and fungal infections. 

The chance of each of these problems occurring depends on the type of transplant being undertaken. 


Any child who receives a stem cell transplant must be isolated for the duration of conditioning therapy and for a period of up to four months after transplant. 

The length of isolation varies according to the type of transplant and the length of time that immunosuppressive therapy continues.  

While in isolation in hospital:

  • your child may receive visits from members of the immediate family and four other designated relatives or friends
  • children (including siblings under the age of six) are not permitted to visit.
  • after discharge from hospital, your child must not return to school or go to public crowded places until the isolation period is over. 

Side effects

You have the highest risk of infections in the first few weeks after transplant. Fortunately, most of these infections are easy to treat with antibiotics.

However, your immune system may need a long time to recover after a transplant. Your health care team will talk with you about ways to reduce your risk of infections.  

Immediate side effects 

  • nausea and vomiting 
  • sores in your mouth 
  • fatigue  
  • low levels of platelets, making it more difficult for your blood to clot  
  • low levels of red blood cells, causing anaemia  
  • diarrhoea.

Long-term side effects 

  • Cataracts, an eye condition that causes cloudy vision 
  • thyroid problems 
  • lung or bone damage 
  • another cancer.

When to call a doctor

Call your doctor right away if your child: 

  • has a fever of 100.4°F (38.0°C) or higher taken orally (in the mouth)  
  • has a runny nose, cough or congestion 
  • has vomiting or diarrhea 
  • has black bowel movements (poops) 
  • has easy bruising or bleeding 
  • has blood in the pee  
  • has a headache, dizziness, or blurred vision 
  • coughs up blood or has a nosebleed that won't stop after a few minutes. 

Resources and more information

  • Childhood Cancer Support keeps families together during their child's cancer treatment in a compassionate and supportive community environment
  • Children’s Cancer Institute is an independent medical research institute in Australia dedicated to curing childhood cancer
  • Caner Australia is a resource that lists information, advice and support organisations available to help you. 
Last updated Thursday 25th January 2024


This factsheet is provided for general information only. It does not constitute health advice and should not be used to diagnose or treat any health condition.

Please consult with your doctor or other health professional to make sure this information is right for you and/or your child.

The Sydney Children’s Hospitals Network does not accept responsibility for inaccuracies or omissions, the interpretation of the information, or for success or appropriateness of any treatment described in the factsheet.

© Sydney Children’s Hospitals Network 2024