Prescriptive birthweight charts can improve the prediction of adverse outcomes in very preterm infants who are small for gestational age

Abstract

Aim: We compared three anthropometric charts to determine which provided the best predictions for adverse outcomes in very preterm small for gestational age (SGA) infants to address a lack of consensus on this subject.

Methods: This was a retrospective cohort study of infants born below 32 weeks, who were admitted to two-level three neonatal intensive care units in The Netherlands from 2008 to 2013. The birthweights of 1720 infants were classified as SGA using a conventional, gender-specific birthweight chart, based on births in The Netherlands between 2000 and 2007, a prescriptive, gender-specific birthweight chart, based on the same data but without risk factors for intrauterine growth restriction (IUGR), and a non-gender-specific foetal weight chart derived from American ultrasonographic measurements.

Results: The conventional, prescriptive and foetal weight charts classified 126 (7.3%), 494 (28.7%) and 630 (36.6%) infants as SGA. The prescriptive chart, which excluded IUGR, identified 368 SGA infants with significantly increased risks of neonatal mortality and morbidity. The 136 SGA infants just classified by the American foetal weight chart were not at increased risk.

Conclusion: The prescriptive birthweight chart, which excluded infants with IUGR, was the most effective chart when it came to identifying clinically important risk increases in SGA infants.

Keywords: Childhood outcomes; Neonatal morbidity; Perinatal mortality; Preterm infants; Small for gestational age.