Perinatal Risk Factors for Postnatal Weight Loss in Late Preterm Infants

Abstract

Purpose: Many studies have reported associations of early postnatal growth failure in preterm infants with several morbidities. However, the risk factors for postnatal weight loss (PWL) in late preterm infants have not been identified. We investigated the inde pendent risk factors for PWL in late preterm infants. Methods: This was a retrospective cohort study. We enrolled 369 late preterm infants born at 34 +0 to 36 +6 weeks gestational age who were admitted to the Soonchunhyang University Cheonan Hospital between 2015 and 2017. PWL% was calculated as (birth weight-lowest weight)/birth weight×100. The infants were classified into lower (<5%) and higher (≥10%) PWL% groups by propensity score matching for gestational age, sex, and birth weight. Perinatal risk factors were analyzed using multivariable logistic regression. Results: The lower and higher PWL% groups included 62 and 31 infants, respectively. Antenatal steroids administered within 1 week before birth (odds ratio [OR], 3.26; 95% confidence interval [CI], 1.015 to 10.465; P=0.047), lower total calorie intake during days 1 to 7 (OR, 0.98; 95% CI, 0.977 to 0.999; P=0.027), and phototherapy (OR, 5.28; 95% CI, 1.327 to 21.024; P=0.018) were independent risk factors for the higher PWL%. Conclusion: Further studies are needed to identify the risk factors that cause high PWL% according to gestational age and short and longterm morbidities based on the degree of PWL.