AbstractIn the years 1964‐66, 338 newborns with a total of 379 gross malformations of the central nervous system and matched‐pair controls were reported to the Finnish Register of Congenital Malformations. Blood samples and detailed maternal histories were obtained from 162 mothers of defective children and their respective controls during the first 2, postpartum months. In the analysis of maternal antibodies the experimental group did not differ in most cases from the controls. However, antibodies against ECHO 7 occurred with significantly (P < 0.005) higher frequency in the experimental group, and when high titers against ECHO 7 were compared this difference was even greater (P < 0.001). On the other hand, antibodies against Coxsackie B1 and high titers against B5 occurred more frequently (P < 0.05) in the control group.