Blood transfusion does not influence the development of malignant tumours

Objective: To investigate whether blood transfusion given to women during c hildbirth favours tumour development in later life. Design: Retrospective cohort study. Setting: County hospital, Sweden. Subjects: 621 women who were given blood transfusions during childbirth com pared with 1216 matched controls who were not given transfusions at the tim e of delivery. Main outcome measures: Overall and cancer-specific mortality, cancer morbid ity, time interval between transfusion and diagnosis or death from cancer. Results: After 21-31 years of follow-up of cancer morbidity and 22-32 years of overall and cancer-specific mortality, we found no significant differen ces between the groups. There were no differences in time from transfusion to diagnosis of malignant disease, or in time from transfusion to death fro m cancer. Conclusion: Blood transfusion given to women during childbirth does not pro mote malignant tumour development in later life. nor does it increase cance r mortality.