Defining small-for-gestational-age: prescriptive versus descriptive birthweight standards
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Descriptive population-based birthweight standards possess low sensitivity in detecting infants with growth impairment. A prescriptive birthweight standard based on a ‘healthy’ subpopulation without risk factors for intrauterine growth restriction might be superior. We created two birthweight standards based on live born, singleton infants with gestational age 24–42 weeks and born in The Netherlands between 2000 and 2007. Inclusion criteria for the prescriptive birthweight standard were restricted to infants without congenital malformations, born to healthy mothers after uncomplicated pregnancies. We defined small-for-gestational-age (SGA) as birthweight <10th percentile and assessed the ability of both standards to predict adverse neonatal outcomes. The prescriptive birthweight standard identified significantly more infants as SGA, up to 38.0 % at 29 weeks gestation. SGA infants classified according to both standards as well as those classified according to the prescriptive birthweight standard only, were at increased risk of both major and minor adverse neonatal outcomes. The prescriptive birthweight standard was both more sensitive and less specific, with a maximum increase in sensitivity predicting bronchopulmonary dysplasia (+42.6 %) and a maximum decrease in specificity predicting intraventricular haemorrhage (−26.9 %) in infants aged 28–31 weeks.
What is Known:
• Descriptive birthweight standards possess low sensitivity in detecting growth restricted infants at risk of adverse neonatal outcomes.
• Prescriptive standards could improve identification of very preterm small-for-gestational-age (SGA) infants at risk of intraventricular haemorrhage.
What is New:
• Prescriptive standards identify more preterm and term SGA infants at risk of major adverse neonatal outcomes.
• Late preterm and term SGA infants classified according to the prescriptive standard are at increased risk of minor adverse neonatal outcomes with potentially harmful implications.
KeywordsSmall for gestational age Intrauterine growth restriction Reference standards Sensitivity and specificity Perinatal mortality and morbidity
Adjusted odds ratio
Cystic periventricular leukomalacia
Hypoxic ischemic encephalopathy
Infant respiratory distress syndrome
Intrauterine growth restriction
The Netherlands Perinatal Registry
Retinopathy of prematurity
We would like to thank The Netherlands Perinatal Registry (PRN) for granting us unlimited access to the required data.
RvL and MH conceived the idea of the manuscript. LH, CH, MH, and RvL were responsible for the study concept and design. LH, CH, and HS analysed the data. LH wrote the initial draft of the manuscript, which was revised by LH, CH, MH, HS, and RvL. All authors approved the final manuscript as submitted and agree to be accountable for all aspects of the work.
Compliance with ethical standards
The manuscript does not contain clinical studies or patient data.
Conflict of interest
The authors declare that they have no conflicts of interest.
No funding was secured for this study.
- 13.Ferdynus C, Quantin C, Abrahamowicz M, Platt R, Burguet A, Sagot P, Binquet C, Gouyon JB (2009) Can birth weight standards based on healthy populations improve the identification of small-for-gestational-age newborns at risk of adverse neonatal outcomes? Pediatrics 123:723–730CrossRefPubMedGoogle Scholar
- 27.Leitner Y, Fattal-Valevski A, Geva R, Eshel R, Toledano-Alhadef H, Rotstein M, Bassan H, Radianu B, Bitchonsky O, Jaffa AJ, Harel S (2007) Neurodevelopmental outcome of children with intrauterine growth retardation: a longitudinal, 10-year prospective study. J Child Neurol 22:580–587CrossRefPubMedGoogle Scholar
- 38.Brouwers HAA, Bruinse HW, Dijs-Elsinga J, van Huis AM, de Miranda E, Ravelli ACJ, Tamminga P, de Winter GA (2013) Stichting Perinatale Registratie Nederland Grote Lijnen 1999–2012 (The Netherlands Perinatal Registry Trends 1999–2012). The Netherlands Perinatal Registry, UtrechtGoogle Scholar