One of the major concerns about ART is the risk of birth defects in children born after in vitro fertilization. We report on a cohort of consecutive children affected with anorectal malformation (ARM) requiring surgical correction in which we found a significantly high proportion (Odds ratio 13.31, 95% confidence limits 4.0-39.6) of children born after ART. Our data is in agreement with the result of a recent epidemiological study in Sweden. Further studies are necessary to define the risk and identify the causes, if any. At present, couples undergoing ART should be informed of the general risk of congenital anomalies, of which, ARM can be suggested as an example.