Diagnostic markers in combination improve the identification of growth-restricted neonates

Abstract

Background The identification of growth-restricted neonates is hampered by the lack of an appropriate diagnostic tool. Aim To determine the value of combining diagnostic markers in detecting growth-restricted neonates. Methods A set of anthropometric indices, nutritional status and placental weight were assessed in the study population soon after birth. Insulin-like growth factor I (IGF-I) and its binding protein 3 (IGFBP-3) were assayed in cord blood. Babies having low values (≤25th centile for gestational age) in 0, 1 or more of four anthropometric indices were classified as Group 250, Group 251 and Group 252, respectively. For statistical evaluation the Mann–Whitney test and a multiple regression analysis were performed. Results One hundred-eighty (180) singleton babies of over 36 weeks of gestational age (GA) were studied. IGF-I, IGFBP-3 levels and placental weight were significantly lower in Group 252 than both Group 250 (P < 0.0001) and Group 251 (p < 0.0001 to p = 0.03). Group 251 and Group 250 did not differ significantly regarding IGF-I and IGFBP-3 levels (p values 0.09 and 0.13, respectively). The combination of anthropometric indices enhanced their ability to predict IGF-I, IGFBP-3 levels and placental weight; the nutritional status of the babies added power to all individual models in predicting the three outcome variables. Analogous results were obtained when the 10th (instead of the 25th) centile for GA was used for the anthropometric indices. Conclusion The combination of simple diagnostic markers of growth restriction can define a reference test with enhanced diagnostic potential compared to the potential of the same markers in isolated use.