Comparison of Intergrowth-21 and Fenton Charts for Extrauterine Growth in Very Low Birth Weigth Infants

Abstract

Abstract Background: The growth of premature babies is expected to be equivalent to healthy fetal growth, but this is rarely achieved in practice. It is predicted that many premature babies, especially severe premature babies, will be discharged with growth restriction. Extrauterine growth retardation (EUGR), which was developed as a definition for this purpose, is defined as being below the 10th percentile according to the growth curve at discharge at the corrected 36th/40th gestational week or the difference between birth and discharge z-score being >1 SD. The aim of our study is to reveal the differences between Intergrowth-21 lie Fenton curve in the evaluation of extrauterine growth. Methods: Infants under 1500 g who were born in Ankara University Neonatal Intensive Care Unit between January 1, 2015 and December 31, 2019 or transferred in the first 24 hours were included. Infants with major congenital anomalies, unknown gestational age, chromosomal anomalies, hydrops fetalis, TORCH infection, infants of substance-abusing mothers and infants who died during hospitalization were excluded. Results: According to the Fenton chart, the rate of EUBG at discharge was 66.3%. There was no significant difference between the groups with and without EUGR in gender, gestational diabetes, maternal smoking during pregnancy, placental abruption, magnesium prophylaxis, development of respiratory distress and the need for intubation in the first 3 postnatal days. When the patients were grouped according to birth weight, the highest rate of EUGR according to the Fenton chart was found in the group with a birth weight ≤1000 g (78.8%) (p=0.036). The proportion of patients defined as SGA by the Intergrowth-21 was significantly higher than the Fenton chart (p<0.001). When EUGR rates according to body weight were evaluated in Fenton and Intergrowth-21 charts; EUGR rate was found to be higher than Fenton (p<0.001). When the mean z-scores of body weight, height and head circumference calculated according to Fenton and Intergrowth-21 charts at birth and discharge were compared, it was observed that body weight and height z-scores at birth and discharge were significantly lower in the negative direction in the Intergrowth-21 (p<0.001). Head circumference z-score was found to have higher values in the Fenton chart than in the Intergrowth-21 at birth and discharge (p<0.001). Conclusions: The results show that when Intergrowth-21 and Fenton charts are compared, the Intergrowth-21 is more sensitive in defining the SGA rate. The Fenton chart is more sensitive in defining EUBG at discharge. These differences observed between the charts make growth monitoring of premature infants and follow-up of comorbidities difficult. Therefore, establishing ideal growth curves is of great importance both during hospitalization and post-discharge follow-up of premature infants.