Cancer Risk among Children Born after Assisted Conception

To the Editor: Williams et al. (Nov. 7 issue) 1 reported no increase in the overall cancer risk among British children born after assisted conception. However, the study has several limitations that deserve attention because the conclusions are important to both future research and the health of children born after assisted conception. The correctness of deterministic linkages depends on the completeness of the data and may vary according to age, with lower rates of linkage for children 1 to 9 years of age. 2 Consequently, it is possible that records were missed or misclassified, leading to an underreporting of the accuracy of . . .