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.