Tejón-Fernández, Marta (M);Armenteros-López, Ana Isabel (AI);Fernández-Rosales, Nazareth (N);Díez-Delgado, Javier (J);Salagre, Diego (D);Galera-Martínez, Rafael (R);Martin-González, Manuel (M);Bonillo-Perales, Antonio (A);

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PLoS One.2025 May 08;20(5):e0323470.doi:10.1371/journal.pone.0323470

Abstract

BACKGROUND: It is not precisely known whether the use of national (Carrascosa 2008) and international growth standards (INTERGROWTH-21) shows good concordance in classifying very low birth weight infants as small-for-gestational-age or whether with the same degree of morbidity and mortality. The aims of this study were a) to evaluate the concordance between small-for-gestational-age neonates weighing <1500 g classified using the national and international standards, and b) to compare the morbidity and mortality of small-for-gestational-age neonates classified by both standards.

METHODS: A retrospective cohort study was conducted with very low birth weight infants. The concordance between the INTERGROWTH-21 and Carrascosa 2008 standards was analyzed, along with differences in gestational age, weight, medical requirements, morbidity, and mortality, among small-for-gestational-age neonates classified by both standards. Small-for-gestational-age was defined as a birth weight z score ≤ -1.28.

RESULTS: A total of 250 neonates weighing <1500 g, who were born between 26 and 36 weeks of gestation, were included. There was a high level of concordance in the classification of small-for-gestational-age between the two standards (Cohen's kappa = 0.80, p < 0.001). A lower incidence was observed when the INTERGROWTH-21 standard was used (31.6%) compared to the Carrascosa 2008 standard (40.8%), p = 0.03. No significant differences were found in mortality or morbidity among neonates classified as small-for-gestational-age by both standards.

CONCLUSION: The Carrascosa 2008 and INTERGROWTH-21 standards classify small-for-gestational-age infants with comparable morbidity and mortality. We recommend the use of the INTERGROWTH-21 standard for its inclusion of multiple pregnancies, diverse ethnicities, and international comparability.