Identification of Growth Patterns in Low Birth Weight Infants from Birth to 5 Years of Age: Nationwide Korean Cohort Study

Abstract

This study aimed to investigate the nationwide growth pattern of infants in Korea according to the birth-weight group and to analyze the effect of growth on development. A total of 430,541 infants, born in 2013 and who received the infant health check-up regularly from 6 months to 60 months of age, were included. The weight, height, head circumferences percentiles, and neurodevelopment using screening tests results were compared among the birth-weight groups. Using longitudinal analysis, the study found a significant difference in height, weight, and head circumference, respectively, according to age at health check-up, birth weight group, and combination of age and birth weight (p < 0.001). The growth parameters at 60 months of age showed a significant correlation with those at 6 months of age especially in extremely low birth weight infants. The incidence of suspected developmental delay was significantly higher in infants with growth below the 10th percentiles than in those with growth above the 10th percentiles. Among 4571 (1.6%) infants with suspected developmental delay results at 60 months of age, birth weight, sex, and poor growth parameters were confirmed as associated factors. This nationwide Korean study shows that poor growth and neurodevelopment outcomes persisted among low-birth-weight infants at 60 months of age. Our findings provide guidance for developing a nationwide follow-up program for infants with perinatal risk factors in Korea.

Growth patterns of preterm infants in Korea

“…In the NHIS study of 430,541 infants covering 99% of national births in 2013, significant differences were noted in height, weight, and HC, respectively, according to age at health check-up, birth weight group, and combination of age and birth weight. (35) The lower birth weight group showed lower catchup growth, even at 60 months. The mean weight, height, and HC percentiles were persistently below 40 among low birth weight and VLBW infants.…”

“…Catch-up growth occurred mainly during the early neonatal period before 24 months and before discharge [ 33 , 34 ]; however, the gains did not always continue over time. In the NHIS study of 430,541 infants covering 99% of national births in 2013, significant differences were noted in height, weight, and HC, respectively, according to age at health check-up, birth weight group, and combination of age and birth weight [ 35 ]. The lower birth weight group showed lower catch-up growth, even at 60 months.…”

“…The lower birth weight group showed lower catch-up growth, even at 60 months. The mean weight, height, and HC percentiles were persistently below 40 among low birth weight and VLBW infants [ 35 ]. The full-term group had greater heights than the preterm group at 8 years of age when the healthy preterm and mid-preterm groups caught up.…”

“…In accordance with other studies, from the NHIS study, infants with poor weight, height, and HC growth were at an increased risk of suspected developmental delay at 60 months of age. ELBW infants were more likely to have a suspected developmental delay (OR, 5.05) than infants with a birth weight of 2,500–4,500 g [ 35 ]. According to Korean retrospective cohort studies, HC at 4 months of PCA was related to favorable neurodevelopmental outcomes at 18 months of PCA, while an HC growth spurt between a postmenstrual age of 35 weeks and a PCA of 4 months is beneficial for preterm AGA infants [ 34 ].…”

Introduction to the Special Issue on Early Child Development: From Measurement to Optimal Functioning and Evidence-Based Policy

“…Different developmental trajectories of specific areas such as language development [ 3 ], nationwide growth patterns [ 6 ] and vision development [ 7 ] were covered by the original papers conducted in South Korea [ 3 , 6 ] and Spain [ 7 ]. Interestingly, Pinero-Pinto et al [ 7 ] present the first study in a large sample of toddlers, describing the developmental correlations between visual and motor systems in typical developing toddlers.…”