452 - Percentile-based reference values of umbilical cord blood insulin-like growth factor-1 in Japanese preterm infants

Poster Number: 452
Publication Number: 452.335

Nobuhiko Nagano, Department of Pediatrics and Child Health, Nihon University School of Medicine, Tokyo, Tokyo, Japan; Masako Aoki, Nihon University School of Medicine, Tokyo, Tokyo, Japan; Daichi Katayama, Department of Pediatrics and Child Health, Nihon University School of Medicine, Toky, tokyo, Tokyo, Japan; Ryoji Aoki, Nihon University School of Medicine, Itabashi-ku, Tokyo, Japan; Tatsuhiko Urakami, Nihon University School of Medicine, Itabashi, Tokyo, Japan; Ichiro Morioka, Nihon University School of Medicine, Itabashi, Tokyo, Japan

Background: Insulin-like growth factor-1 (IGF-1) plays an important role in fetal growth and organ development. IGF-I has also been reported to be associated with newborn complications, such as retinopathy of prematurity, chronic lung disease, neurodevelopmental disorders, and failure to thrive. To date, no percentile-based reference values of umbilical cord blood IGF-1 has been established in preterm infants.

Objective: To create percentile-based reference values for umbilical cord blood IGF-1 in Japanese preterm infants as a function of gestational age (GA) and physique at birth.

Design/Methods: A hospital-based prospective study was conducted at Nihon University Itabashi Hospital with approval by the Ethics Committees (no. RK190910-3). Newborns born at < 37 wks gestational age (GA) between 2019 and 2021 were enrolled. Infants were first classified into the three GA groups: extremely preterm, < 28 wks; early preterm, 28–33 wks; and late preterm, 34–36 wks. Next, newborns were sub-classified as small-for-gestational age (SGA, birthweight (BW) < 10th percentile) or non-SGA (BW \geq10th percentile). Median umbilical cord blood IGF-1 levels were then compared between each group.

Results: At total of 205 preterm newborns born at our hospital were enrolled: 32 were extremely preterm (8 SGA; 24 non-SGA), 83 early preterm (28 SGA; 55 non-SGA), and 90 late preterm (21 SGA; 69 non-SGA). Overall median umbilical cord blood IGF-1 value was 30 ng/mL (n=205). In extremely preterm infants, IGF-1 levels were significantly lower than that in early preterm or late preterm infants (p < 0.001, Table 1). No significant difference in those born SGA was found between extremely preterm and early preterm infants (p=0.504, Table 2). In non-SGA infants, median IGF-1 levels were significantly different between extremely preterm and early preterm infants (p < 0.001, Table 2).Conclusion(s): We established percentile-based reference values of umbilical cord blood IGF-1 in preterm infants. Reference values should be applied based on extent of prematurity and SGA vs non-SGA.
Umbilical cord blood IGF-1 level by GA
Umbilical cord blood IGF-1 level in non-SGA and SGA infants by GA