目的 探索儿童肿瘤治疗相关重度血小板减少症（cancer therapy⁃related thrombocytopenia, CTRT）发生情况及影响因素。 方法 通过前瞻性调查，纳入2023年11月—2024年8月于上海交通大学医学院附属上海儿童医学中心的1 047例儿童肿瘤住院患者。依据患儿是否发生重度CTRT进行分组，采用多因素logistic回归分析筛选危险因素。 结果 343例（32.76%）发生重度CTRT。多因素logistic回归分析显示，复发、重度CTRT既往史、营养风险异常、使用超过3种抗肿瘤药物、方案中含铂类药物/阿糖胞苷/蒽环类药物、治疗前血小板计数<100×10⁹/L与重度CTRT密切相关（P<0.05）。 结论 儿童重度CTRT发生率较高，受到病史（复发、重度CTRT既往史）、治疗方案（超过3种抗肿瘤药物、方案中含铂类药物/阿糖胞苷/蒽环类药物）及健康状况（营养风险异常、治疗前血小板计数<100×10⁹/L）等综合因素影响，通过病史评估、健康评估、治疗方案识别高风险患儿，及时给予预防性及支持性照护。

Objective To investigate the incidence of severe cancer therapy-related thrombocytopenia (CTRT) and associated factors in children. Methods A prospective observational study was conducted among 1 047 pediatric inpatients with cancer at Shanghai Children's Medical Center, Shanghai Jiao Tong University School of Medicinefrom November 2023 to August 2024. Patients were divided into two groups based on the occurrence of severe CTRT. Multivariable logistic regression analysis was used to identify risk factors for severe CTRT. Results Severe CTRT occurred in 343 patients (32.76%). Multivariable logistic regression analysis showed that disease relapse, history of severe CTRT, nutritional risk, use of >3 antineoplastic agents, inclusion of platinum-based agents/cytarabine/anthracyclines in the regimen, and pre-treatment platelet count <100×10⁹/L were significantly associated with severe CTRT (P<0.05). Conclusions The incidence of severe CTRT in children is relatively high, and it is influenced by multiple factors including medical history (relapse, previous severe CTRT), treatment regimen (>3 antineoplastic agents, inclusion of platinum-based agents/cytarabine/anthracyclines), and health status (nutritional risk, pre-treatment platelet count <100×10⁹/L). High-risk children should be identified through comprehensive assessment of medical history, health condition, and treatment regimen to provide timely preventive and supportive care.