Factors influencing the catch-up growth of preterm births at two years of corrected age

Abstract

Abstract Purpose This study aimed to analyze the growth of preterm infants after birth regarding weight, length, and head circumference (HC) and determine the risk factors affecting their catch-up growth. Methods Anthropometric data and clinical information from 288 preterm infants were collected. Z-scores were calculated using the World Health Organization Anthro software. Logistic regression analysis assessed the risk factors for catch-up growth in preterm births. Results The percentage of preterm infants with z-scores <-1.3 for weight, length, and HC decreased from 13.78%, 11.31%, and 7.42–6.81%, 4.26%, and 4.68%, respectively, between 0 and 24 months of corrected age (CA). The weight z-score increased between CA 0 and 3 months in non-small for gestational age (SGA); the increased weight z-score in SGA extended to CA 9 months. Non-SGA had elevated length z-scores from CA 0 to 6 months, and SGA length z-scores were elevated for an extended period until CA 9 months. Z-score differences in weight and length of SGA and non-SGA preterm infants decreased with increasing CA. Gestational age (OR = 2.814, 95%CI: 1.32–5.997) and birth weight (OR = 0.998, 95%CI: 0.997–0.999) were risk factors for catch-up growth at CA 24 months. Conclusion Most catch-up growth occurs in the first year of life. Compared to the non-SGA group, preterm infants in the SGA group showed more pronounced and prolonged catch-up growth, particularly in weight and length. We concluded that gestational age and birth weight were risk factors for catch-up growth.