Growth Outcomes of Small for Gestational Age Infants
Creators: name: Maguire, Fiachra J
name: Loftusei@Tcd.Ie
name: Carolasi@Tcd.Ie
name: Degibbon@Tcd.Ie
name: Obrienoi@Tcd.Ie
name: Oconnn15@Tcd.Ie
name: Byrnej34@Tcd.Ie
Publisher: name: figshare
Year: 2017
Subjects: subject: 111403 Paediatrics
subject: FOS: Clinical medicine
subject: FOS: Clinical medicine
subject: Medicine
subject: 111706 Epidemiology
subject: FOS: Health sciences
subject: FOS: Health sciences
subject: 110306 Endocrinology

description: Title: Childhood growth outcomes of children born small for gestational age<br> Authors: O’Connor N, O’Brien O, Carolan S, Gibbons D, Loftus E, Byrne J, Maguire F (Presenter). Institution: School of Medicine, Trinity College Dublin, University of Dublin, Ireland Introduction ‘Small for gestational age” (SGA) defines infants whose birth weight or crown-heel length is 2 standard deviations (SDs) below the mean for their appropriate gestational age (AGA). Approximately 3-5% of neonates are born SGA. This cohort is estimated to account for 1 in 5 children (and adults) who are short in stature. SGA is associated with poor outcomes in terms of growth and metabolism. Consideration should be given to relevant potential treatments for this cohort, such as growth hormone. We reviewed the literature to provide an overview of this condition and contextualised our findings in an Irish population using data from the ‘Growing Up in Ireland’ (GUI) study. Methods PubMed, Embase and The Cochrane Library databases were searched using the following medical subject headings (MeSHs): [“small for gestational age” AND (growth OR length OR height OR weight OR circumference)]. Papers were included if they were review articles, contained these MeSH terms in the title or abstract, the full-text was available online in English, and contained anthropometric data on SGA children. Following automated duplicate removal, included papers underwent independent screening. Papers were manually screened based on their title/ abstract and then full-text, with inclusion or exclusion decided by 2 of 3 authors’ votes. Data from the GUI study was analysed using R and Stata software. Birth height was standardised according to gestational age. Growth measures were standardised for sex. Distributions of outcome variables were examined using robust graphical methods. Univariate poisson regression was employed to examine the relative risk of SGA on quintiles of growth outcomes at 9 months, 3 and 5 years of age. A sex-adjusted height below two standard deviations was identified as a significant cut-score from the literature. Univariate logistic regression was employed to examine the likelihood of this outcome in the SGA group. An alpha level of 0.95 was used. Results In total, 493 search results were identified. 97 of these results were removed as duplicates, leaving 396 unique results for manual screening. 352 papers were excluded during screening, leaving 44 for inclusion in the research project. The GUI cohort consisted of 12,121 children in Ireland, 56% of whom were female. Those born SGA were 29%, 16% and 12% more likely to fall in a height decile below that of their average for gestational age peers at 9 months, 3 and 5 years respectively. At 5 years of age the SGA group demonstrated a likelihood of falling 2 SD below the sex-adjusted mean, five-fold over their peers (OR: 5.40, 95% CI: 2.86, 10.20). Graphical visualisations were plotted to aid interpretation of outcomes for the SGA group in this dataset. Discussion Results from literature are summarised under the following sub-headings; Catch-Up Growth, Metabolism, Puberty and Growth Hormone Treatment.. Catch-up growth is an important metric for those born SGA. 85% achieve height within 2SD of normal by 2 years of age. 10-15% don’t catch-up and are at increased risk of persistent short stature at 10 years. Half of this group experience spontaneous catch-up during remaining childhood with another half persisting as short to adulthood. Prematurity in SGA is associated with delay and decreased likelihood of catch-up growth, with similar long-term outcomes as described above. Infants born SGA who experience catch-up growth have a higher risk for developing obesity, type-2 diabetes, hypertension and metabolic syndrome in later life. A high growth velocity during infancy and childhood appears to predict insulin resistance. This suggests that catch-up growth may be due to a ‘thrifty phenotype’ (i.e. metabolic compensation for scarce nutrients in utero).. Onset of puberty is earlier in SGA versus AGA children, but still within the normal age range, at least in females. More rapid bone maturation and earlier peak height velocity cause earlier fusion of the epiphyseal growth plates and premature termination of growth. SGA children who don’t demonstrate catch-up growth often demonstrate abnormalities in the Growth Hormone-Insulin-like Growth Factor (GH-IGF) axis. GH therapy is licensed in children 4 years or older for height &lt;2.5SD below the mean, height velocity &lt;0SD for age, or predicted height &lt;1SD below mid-parental height. Therapy can normalise adult stature and better outcomes are associated with younger age at treatment, higher GH dose, high mid-parental height, duration of treatment and exon 3 deletions in GH receptor. In conclusion, SGA is a multifactorial condition which predisposes children to both the psychosocial consequences of short stature and the chronic health effects of metabolic dysregulation. GH is a safe and effective therapy which can improve growth outcomes whilst attenuating the metabolic consequences of catch-up growth.