Barnabei et al offered a possible explanation of the presumed association between autism and labor induction or augmentation as reported by Gregory et al. However, as we espoused in our editorial as well as in our reply to the letter to the editor by Miranda et al, the data so far do not support that such an association exists because in the study by Gregory et al, the diagnosis of autism was incorrect for the infants born during the initial years of the study (years 1990-1995). When the correct diagnostic criteria for autism were applied in the last 3 years (birth years 1996-1998), the authors reported no association between the augmentation or induction of labor and the risk of autism.

As a matter of fact, we urged Miranda et al to seriously consider retracting their initial conclusion regarding the presumed association between the induction or augmentation of labor and autism risk. If future studies show that an association between autism and labor induction or augmentation indeed exists, then we agree with Barnabei et al that abnormal cellular calcium homeostasis in the uterus may be one possible etiological factor leading to labor abnormalities and the need for labor induction or augmentation.