Cut-Off Points of Head, Chest, and Arm Circumferences to Identify Low Birthweight: Meta-Analysis

Background: The cut-off points of newborn anthropometric variables to identify low birthweight (i.e., birthweight < 2500 g) have varied between studies or even within the same study. Methods: Meta-analysis was performed to summarize cut-off points in studies judged as good quality based on the Quality Assessment of Diagnostic Accuracy Studies tool (QUADAS). PubMed (MEDLINE) and nine other databases were searched (January, 2015). PubMed related-citations and references of potentially eligible articles and related reviews were also investigated. The Egger test was used to assess publication bias. Results: With respect to head, chest, and arm circumferences, the cut-off points that involved no publication bias could be summarized based on the data from large numbers of newborns (=21,793, 8917, and 12,912, respectively) in relatively sufficient numbers of studies (=17, 15, and 19, respectively). The optimal cut-off points to identify low birthweight were 33.0 cm (95% confidence interval [CI], 32.8 - 33.2), 30.4 cm (95% CI, 30.3 - 30.6), and 9.3 cm (95% CI, 9.1 - 9.4) for head circumference, chest circumference, and arm circumference, respectively. The summarized cut-off point of birth height, i.e., 47.2 cm (95% CI, 46.7 - 47.7), used to identify low birthweight involved publication bias (n = 13). Conclusion: The cut-off points were determined to identify low birthweight using head, chest, and arm circumferences.