Growth patterns over 2 years after birth according to birth weight and length percentiles in children born preterm

Hokkaido birth cohort study in Japan on the growth trajectory of children born with low birth weight until 7 years of age

BACKGROUND

Low birth weight (LBW) is a significant global health concern with potential health risks and developmental implications for infants. Catch-up growth, an accelerated growth following an inhibition period, may partially compensate for growth deficits in LBW children.

AIMS

This study investigated the prevalence of LBW and catch-up growth in height, weight, and body mass index (BMI) among LBW children in Japan, identified factors associated with LBW, and explored the potential for catch-up growth at different ages up to seven years.

STUDY DESIGN AND SUBJECTS

The Hokkaido birth cohort study included 20,926 pregnant Japanese women recruited during their first trimester from 37 hospitals and clinics. Follow-up assessments were conducted in children up to seven years of age, tracking LBW children's growth and development using the Maternal and Child Health Handbook, and providing valuable insights into catch-up growth patterns.

OUTCOME MEASURES

LBW was defined as a neonatal birth weight of <2500 g. The primary outcomes were catch-up growth in height, weight, and BMI at different ages. Z-scores were calculated to assess growth parameters with catch-up growth, defined as a change in z-score (> 0.67) between two time points.

RESULTS AND CONCLUSIONS

A LBW was prevalent in 7.6 % of the cohort, which was lower than that reported in other Japanese studies. Among LBW children, 19.3 % achieved catch-up growth in height by age seven, and 10.6 % in weight. Catch-up growth in LBW children could partially offset these deficits. Further research will help understand the long-term outcomes and inform interventions for healthy development.

Growth outcome at 2 years using Fenton and Intergrowth-21st charts in infants less than 1500 g

INTRODUCTION

There is no consensus on which neonatal chart is best to use in very low birth weight (VLBW) infants. The aim of the study was to compare the Fenton 2013 and Intergrowth-21st (IW-21) charts based on their predictive ability for somatometry at 2 years, as well as to analyze factors related to short stature at 2 years.

MATERIAL AND METHODS

Cohort of children with VLBW born between 2002 and 2017. Association between neonatal somatometry (z-score by Fenton and IW-21) and risk of short stature (<-2 DS), head circumference <-2 DS and malnutrition at 2 years (BMI < -2 DS) was analyzed (WHO charts).

RESULTS

513 children with a mean gestational age of 30.05 ± 2.5 weeks were included. Birth and discharge weight z-score by Fenton and IW-21 were useful for predicting risk of short stature and malnutrition at 2 years (without differences in the AUC of the ROC curves). Weight z-score at discharge was also useful for predicting head circumference < -2 DS. At 2 years, prevalence of short stature, head circumference < -2 DS, and malnutrition was 17.2, 4.1, and 6.1%, respectively. Low weight for gestational age and length of stay were identified as independent risk factors for short stature at 2 years.

CONCLUSIONS

Discharge weight z-score is useful for predicting risk of short stature, malnutrition and head circumference < -2 DS at 2 years in very low birth weight children, with no statistical difference between using Fenton or IW-21 charts.

Long-term effectiveness of growth hormone therapy in children born small for gestational age: An analysis of LG growth study data

Purpose

Growth hormone (GH) treatment has been used to improve growth in short children who were born small for gestational age (SGA). The aim of this study was to investigate the long-term efficacy of GH treatment in these children.

Methods

Data from a multicenter observational clinical trial (ClinicalTrials.gov NCT01604395, LG growth study) were analyzed for growth outcome and prediction model in response to GH treatment. One hundred fifty-two children born SGA were included.

Results

The mean age of patients born SGA was 7.13 ± 2.59 years. Height standard deviation score (SDS) in patients born SGA increased from -2.55 ± 0.49 before starting treatment to -1.13 ± 0.76 after 3 years of GH treatment. Of the 152 patients with SGA, 48 who remained prepubertal during treatment used model development. The equation describing the predicted height velocity during 1st year of GH treatment is as follows: the predictive height velocity (cm) = 10.95 + [1.12 x Height SDS at initial treatment (score)] + [0.03 x GH dose (ug/kg/day)] + [0.30 x TH SDS at initial treatment (score)] + [0.05 x age (year)] + [0.15 x Weight SDS at initial treatment (score)] ± 1.51 cm.

Conclusions

GH treatment improved growth outcome in short children born SGA. We also developed a prediction model that is potentially useful in determining the optimal growth outcome for each child born SGA.

Trial registration

ClinicalTrials.gov Identifier: NCT01604395.

Growth patterns of preterm infants in Korea

With advancements in neonatal care and nutrition, the postnatal growth of preterm infants has improved; however, it remains an issue. Accurate assessments of growth using a standardized reference are needed to interpret the intrauterine and postnatal growth patterns of preterm infants. Growth in the earlier periods of life can contribute to later outcomes, and the refinement of postnatal growth failure is needed to optimize outcomes. Catchup growth occurs mainly before discharge and until 24 months of age, and very low birth weight infants in Korea achieve retarded growth later in life. Knowing an infant's perinatal history, reducing morbidity rates during admission, and performing regular monitoring after discharge are required. Preterm infants with a lower birth weight or who were small for gestational age are at increased risk of poor neurodevelopmental outcomes. Furthermore, poor postnatal growth is predictive of adverse neurodevelopmental outcomes. Careful monitoring and early intervention will contribute to better development outcomes and national public health improvements.