Loading
Chemotherapy can lower platelets, the blood cells that stop bleeding. A child who is not bleeding is usually given a platelet transfusion only when the count falls below 10, because giving them earlier does not prevent more bleeding. Higher counts are needed before a lumbar puncture or surgery, and for a child who is bleeding.
The 2025 AABB and ICTMG international guidelines (GRADE, 21 randomised trials and 13 observational studies), endorsed by the Children's Oncology Group in February 2026, favour restrictive platelet use. For non-bleeding patients with hypoproliferative thrombocytopenia receiving chemotherapy or undergoing allogeneic stem cell transplant, transfuse at a platelet count below 10 × 10³/μL (strong, moderate). Before lumbar puncture, transfuse below 20 × 10³/μL (strong, moderate), recognising an extremely low rate of spinal haematoma. Preterm neonates without major bleeding are transfused below 25 × 10³/μL (strong, high). A good practice statement asks clinicians to weigh symptoms, bleeding history, medicines, values and the whole clinical picture. NICE NG24 (children over 1 year, extrapolated from adults) agrees on prophylaxis below 10 × 10⁹/L, gives a threshold of 30 × 10⁹/L for clinically significant (WHO grade 2) bleeding and up to 100 for severe or critical-site bleeding, considers raising the count above 50 for invasive procedures or surgery, and advises no prophylactic platelets for bone marrow aspiration and trephine. One dose at a time, then reassess the child and recheck the count.
Why: The count is a guide, not the only reason to transfuse or not.
“Consider symptoms, signs, other laboratory parameters, bleeding history, medications, patients’ values and preferences, alternative therapies, and overall clinical context when deciding to perform a platelet transfusion on a particular patient.”
Children's Oncology Group 2026 · Good practice statement
Why: Transfusing at higher counts did not reduce bleeding or deaths in the trials, and each transfusion carries a risk of reactions.
“Evidence demonstrated that restrictive transfusion strategies probably did not cause increases in mortality or bleeding relative to liberal strategies across predefined clinical populations.”
AABB and the International Collaboration for Transfusion Medicine Guidelines, JAMA 2025 · Strong / Moderate
Why: Bleeding into the spine after a lumbar puncture with low platelets was found to be extremely rare, so a lower threshold spares children transfusions.
“Exceedingly low incidence of spinal hematoma was identified in patients with thrombocytopenia undergoing lumbar puncture.”
AABB and the International Collaboration for Transfusion Medicine Guidelines, JAMA 2025 · Strong / Moderate
Why: NICE classes it as a procedure with a low risk of bleeding, so platelets are not given just for it.
“Do not offer prophylactic platelet transfusions to people having procedures with a low risk of bleeding, such as adults having central venous cannulation or any people having bone marrow aspiration and trephine biopsy.”
Why: Riskier procedures need a higher count, and the brain and the back of the eye are where bleeding does most harm.
Why: Bleeding with a low count is the clearest reason to give platelets.
Why: Bleeding in these places can cause lasting harm, so the count is kept higher.
Why: A single dose is usually enough, and checking avoids giving more than needed.
“Reassess the person's clinical condition and check their platelet count after each platelet transfusion, and give further doses if needed.”
How care is usually carried out, read from the guidelines and standards cited. Your own team's protocol and their judgement come first; this page is for understanding it, not for doing it yourself.
For prophylaxis during chemotherapy or after allogeneic transplant the guidelines agree: transfuse a non-bleeding child below 10 (AABB and ICTMG 2025, strong, moderate, endorsed by COG for children; NICE NG24, for people over 1 year). They differ before lumbar puncture: AABB and ICTMG recommend a threshold of 20 × 10³/μL (strong, moderate), on evidence that spinal haematoma is exceedingly rare, while NICE NG24 has no lumbar puncture threshold and considers raising the count above 50 × 10⁹/L for invasive procedures in general, a 2015 recommendation extrapolated from adults. The 2025 international guideline is the newer and the one COG endorses for children.
Children's Oncology Group 2026 · AABB and the International Collaboration for Transfusion Medicine Guidelines, JAMA 2025 · NICE 2015
Where it differs: Treats a lumbar puncture as an invasive procedure and considers raising the count above 50 × 10⁹/L, rather than transfusing only below 20.
Evidence: NICE does not grade recommendations and wrote this one in 2015 for invasive procedures in general, extrapolated to children from adult evidence. AABB and ICTMG 2025 give a strong recommendation, moderate certainty, for a threshold of 20 × 10³/μL specifically for lumbar puncture.
NICE 2015 · AABB and the International Collaboration for Transfusion Medicine Guidelines, JAMA 2025
| Recommendation | Grade, as printed | Source |
|---|---|---|
| Prophylactic transfusion below 10 × 10³/μL during chemotherapy or after allogeneic transplant | Strong / Moderate | Children's Oncology Group 2026 |
| Transfusion below 20 × 10³/μL before lumbar puncture | Strong / Moderate | Children's Oncology Group 2026 |
| Preterm neonates without major bleeding transfused below 25 × 10³/μL | Strong / High | Children's Oncology Group 2026 |
| No prophylactic platelets for non-bleeding adults after autologous transplant or with aplastic anaemia “For hypoproliferative thrombocytopenia in nonbleeding adults undergoing autologous stem cell transplant or with aplastic anemia, prophylactic platelet transfusion is not recommended.” | conditional recommendation, low/very low-certainty evidence | AABB and the International Collaboration for Transfusion Medicine Guidelines, JAMA 2025 |
Shares National Institute for Health and Care Excellence, Allogeneic stem cell transplantation, Children's Oncology Group (COG), Childhood cancers (all types) and the tags protocol, paediatric.
Shares Thrombocytopenia, Transfusion support and anaemia management, National Institute for Health and Care Excellence and the tags protocol, transfusion.
Shares Intrathecal therapy (lumbar puncture, Ommaya reservoir), National Institute for Health and Care Excellence, Children's Oncology Group (COG), Childhood cancers (all types) and the tags protocol, paediatric.
Shares National Institute for Health and Care Excellence, Allogeneic stem cell transplantation, Children's Oncology Group (COG), Childhood cancers (all types) and the tags protocol, paediatric.
Shares Allogeneic stem cell transplantation, Children's Oncology Group (COG), Childhood cancers (all types) and the tags protocol, paediatric.
Shares Allogeneic stem cell transplantation, Children's Oncology Group (COG), Childhood cancers (all types), Acute lymphoblastic leukaemia and the tags protocol, paediatric.
Shares Thrombocytopenia, Allogeneic stem cell transplantation, Children's Oncology Group (COG), Childhood cancers (all types) and the tags protocol, paediatric.
Shares Allogeneic stem cell transplantation, Children's Oncology Group (COG), Childhood cancers (all types), Acute lymphoblastic leukaemia and the tags protocol, paediatric.