Alternative therapies for nausea and vomiting of pregnancy

CRD COMMENTARY: The author conducted a very thorough narrative review of the literature and addressed issues of bias by searching for unpublished data and non-English abstracts and articles, although any non-English material found was not read. The inclusion criteria for the individual trials and their participants were stated. However, the author did not state whether the quality of the primary trials was assessed or how judgements were made about the inclusion of studies. The author listed the primary trials on acupressure in tabular format but only discussed the data from the studies on ginger, pyridoxine and hypnosis in the text. The criteria and methods for the data extraction were not stated. There were several cases of missing data from the primary studies of ginger, pyridoxine and hypnosis, e.g. dosages, the numbers of participants and reported results. The accuracy of the author's conclusions are difficult to assess since the results of the trials within each grouping were not presented or discussed in an explicit pooled format. In the discussion of the acupressure trials the author's conclusions were supported by the data.