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Annotations and Reflections

Dear Editor, We have observed an increasing interest in the study of childhood neurodevelopment following in utero exposure to drugs [1–7]. We appreciate the efforts to address an important, difficult and poorly studied subject, but we believe there are some major methodological pitfalls to avoid. With specific reference to recent papers, we wish to discuss some general and specific, methodological issues that we believe complicate the interpretation of such data. Of special interest in this perspective is the publication by Brandlistuen et al. [1] that has stirred some controversy and attracted significant public attention [8,9].