Objectives To determine the diagnostic accuracy of small-for-gestational-age (SGA; <10th centile) status for infant mortality and adverse school-age outcomes in infants born extremely preterm (EP; <28 weeks’ gestation).
Design Geographical cohort studies.
Setting The state of Victoria, Australia.
Patients For mortality, live births 22–27 weeks’ gestation from 2009 to 2017 offered active care after birth. For school-age outcomes, survivors to 8 years’ corrected age born in 1991–1992, 1997 or 2005.
Exposures SGA <10th centile on four commonly used growth references: three derived from neonatal data (Fenton, UK-WHO and Intergrowth Newborn Size) and one from fetal data (Intergrowth Estimated Fetal Weight).
Main outcome measures (a) Infant mortality; (b) major neurodevelopmental disability, and poor performance on tests of IQ, academic achievement, motor function, and executive function.
Results Infant mortality data were available for 2040 infants, and neurodevelopmental data for 499 children. Diagnostic accuracy of SGA status was low overall and varied with the growth reference. Positive predictive values for infant mortality ranged from 18% to 21%, only marginally higher than its 18% prevalence. Compared with a prevalence of 17%, positive predictive values for major neurodevelopmental disability ranged from 30% to 38% for the neonatal growth references but was only 20% for Intergrowth Estimated Fetal Weight. SGA status was also associated with lower IQ, poor academic achievement and poor motor performance.
Conclusions Among infants born EP, the diagnostic accuracy of SGA status was low for both infant mortality and adverse neurodevelopmental outcomes at school age, but importantly varied with the growth reference used to identify SGA status.
- Infant Development
- Intensive Care Units, Neonatal
Data availability statement
All data relevant to the study are included in the article or uploaded as supplemental information.
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Collaborators Victorian Infant Collaborative Study Group: Jeanie Cheong, Peter Anderson, Merilyn Bear, Rosemarie Boland, Alice Burnett, Margaret Charlton, Marissa Clark, Noni Davis, Lex Doyle, Julianne Duff, Leah Hickey, Elisha Josev, Katherine Lee, Rheanna Mainzer, Marion McDonald, Bronwyn Novella, Joy Olsen, Gillian Opie, Gehan Roberts, Katherine Scott, Alicia Spittle, Penelope Stevens, Anne-Marie Turner.
Contributors LWD and JLYC conceptualised and designed the study, coordinated and supervised data collection, analysed the data, drafted the initial manuscript, and critically reviewed and revised the manuscript. JC drafted the initial manuscript, and critically reviewed and revised the manuscript. RAB, EKJ and MC collected data, and critically reviewed and revised the manuscript. RM analysed the data and critically reviewed and revised the manuscript. SCK and GR critically reviewed and revised the manuscript. PJA conceptualised and designed the study, coordinated and supervised data collection, and critically reviewed and revised the manuscript for important intellectual content. LWD accepts full responsibility for the work and the conduct of the study, had access to the data, and controlled the decision to publish.
Funding Supported by grants from the National Health and Medical Research Council of Australia (Centre of Clinical Research Excellence #546519; Centre of Research Excellence #1060733 & #1153176; Project Grant #108702; Leadership Fellowship #1176077 to PJA), the Medical Research Future Fund of Australia (Career Development Fellowship #1141354 to JC), and the Victorian Government’s Operational Infrastructure Support Program.
Disclaimer The funding sources had no role in the study design; in the collection, analysis and interpretation of data; in the writing of the report; and in the decision to submit the paper for publication. The conclusions, findings, opinions and views or recommendations expressed in this paper are strictly those of the authors. They do not necessarily reflect those of CCOPMM.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.
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