ICSI is now used to enable men with severely damaged spermatogenesis to father children in situations formerly considered hopeless and in which very few spermatozoa can be obtained. This has led to worries that children may be born with a fetal abnormality that would otherwise not have occurred. This is because the selective processes of female genital tract and egg coverings are being bypassed to enable defective sperm, that would not otherwise have done so, to fertilize eggs. It is therefore very reassuring that the collected fetal abnormality statistics from ICSI centres do not indicate any increase in congenital malformations compared with the general population. However, the indications for ICSI are constantly being extended to include fertilization with immature sperm forms and it will be particularly important to continue to monitor fetal abnormality rates with detailed subgroup analysis according to the clinical and molecular diagnoses of the father.