The present study investigated a possible correlation between prenatal stress and the onset of infantile spasms. A total of 120 infants (60 cases, 30 positive controls, and 30 negative controls) went through routine etiologic screening. The Pregnant Woman Life Event Scale was used to investigate and evaluate the degree of prenatal stress of the mothers in the three infant groups. Etiologic analyses indicated no statistical difference between the infantile spasms group and the other epilepsy control group. There was a significant difference in the degree of prenatal stress among mothers of the three infant groups, with higher maternal prenatal stress levels in the infantile spasms group than in the other epilepsy group (positive control) or the normal control group (P < 0.05). Regression analysis with the dummy variable indicated that the onset risk of infantile spasms correspondingly increased with the degree of maternal prenatal stress for stress levels 1-3 (out of four levels) (P < 0.05). Within a certain range, the onset risk of infantile spasms increases with the degree of prenatal stress. (C) 2010 by Elsevier Inc. All rights reserved.