In epidemiologic research, there is no standard approach for accounting for gestational age (GA) at birth when interpreting postnatal anthropometric data in analyses of cohorts that include children born preterm (CBP). A scoping review was conducted to describe analytical approaches to account for GA at birth when applying the WHO Growth Standards (WHO-GS) to anthropometric data in epidemiologic studies. We searched PubMed, Scopus, MEDLINE, Embase, and Web of Science for studies that applied WHO-GS, included CBP in the study population, had access to data within 1 mo of age, and were published between 2006 and 2015 in English. Of the 80 included studies that used the WHO-GS, 80% (64 of 80) included all children regardless of GA, whereas 20% (16 of 80) restricted analyses that used WHO-GS to term-born children. Among the 64 studies that included all children, 53 (83%) used chronological age and 11 (17%) used corrected age for CBP. Of the 53 studies that used chronological age, 12 (23%) excluded data that were likely contributed by CBP (e.g., very low birth weight or extremely low outlying z scores) and 19 (36%) adjusted for or stratified by GA at birth in regression analyses. In summary, researchers commonly apply WHO-GS to CBP, usually based on chronological age. Methodologic challenges of analyzing data from CBP in the application of WHO-GS were rarely explicitly addressed. Further efforts are required to establish acceptable approaches to account for heterogeneity in GA at birth in the analysis of post-term anthropometric data in epidemiologic research.
Keywords: World Health Organization Growth Standards (WHO-GS); gestational age; growth; infants; pediatrics; preterm birth; review.
© 2015 American Society for Nutrition.