Chungnam national university Sejong hospital sejong-si, Taejon-jikhalsi, Republic of Korea
Background: Fetal growth restriction (FGR) is defined differently from small for gestational age (SGA) and has a significant impact on the prognosis of newborns or preterm infants. Non-invasive body measurements such as weight are commonly used as indicators, although they are simple and broad in scope; however, it is possible for AGA (Appropriate for Gestational Age) with FGR. There is a need for proportional anthropometric measurement index of intrauterine fetal growth and nutritional status. Objective: This study was designed to determine the correlation between the body mass index (BMI) z- score at birth as an index of intrauterine fetal growth and the neurodevelopmental outcomes at age 2 years in very low birth weight (VLBW) infants. Design/Methods: The BMI z-scores at birth were calculated using the lambda-mu-sigma method. 11,127 VLBW infants born from January 2013 to December 2018 were investigated. The low, normal, and high BMI z-score groups were defined as follows: BMI z-scores of <−1.28, −1.28 to 1.28, and >1.28, respectively. Surviving VLBW infants were followed up at 18-24 months CA by pediatricians and/or rehabilitation doctors. Developmental delay at 18–24 months of CA was assessed by pediatricians or rehabilitation doctors using the second edition of the Bayley Scales of Infants Development (BSID-II), the third edition of the BSID (BSID-III), and the Korean Developmental Screening Test (K-DST). Results: the infants’ development was assessed using the Bayley Scales of Infant Development (BSID) or the Korean Developmental Screening Test (K-DST). The developmental delay was defined as less than −1 standard deviation in any domain of the BSID or less than −2 SD in any domain of the K-DST. Assessments were performed at the 18-24 months corrected age. The odds of developmental delay were higher in the low-BMI group than in the normal-BMI group, with an adjusted odds ratio of 2.00 (95% confidence interval [CI], 1.02–3.95) for the K-DST and 3.16 (95% CI, 1.67-6.00) for the BSID. In contrast, no significant differences in the outcomes were found between the high and normal-BMI groups.
Conclusion(s): Preterm infants with low-BMI z-scores at birth have an increased risk of developmental delay compared with those with normal-BMI z-scores. The accuracy of developmental delay diagnosis improves when both birth weight and BMI (Body Mass Index) are concurrently applied.
