The Publisher and Editor are issuing an Expression of Concern on the article titled “Effect of Daily Consumption of Probiotic Yogurt on Oxidative Stress in Pregnant Women: A Randomized Controlled Clinical Trial” [Ann Nutr Metab. 2012;60:62–68, DOI: 10.1159/000335468] by Zatollah Asemi, Shima Jazayeri, Mohammad Najafi, Mansoreh Samimi, Vahid Mofid, Farzad Shidfar, Hossein Shakeri, and Ahmad Esmaillzadeh.

Following publication, concerns were raised about the article by Asemi et al. regarding sample size discrepancies within the article, discrepancies in site description and dates between the trial registration and the article, overlap with other articles with the same trial registration number without acknowledgement, inconsistencies in the application of exclusion criteria and reporting of a non-primary outcome measure without declaration.

The concerns have been investigated by the National Committee for Ethics in Biomedical Research at the Iranian Ministry of Health and Medical Education. As our investigation is ongoing, we are issuing an Expression of Concern and readers should thus interpret the data presented in the article with caution. Appropriate editorial action will be taken once the investigation is concluded.