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Minerva Pediatrics 2021 Dec 03

DOI: 10.23736/S2724-5276.21.06663-5


language: English

Perinatal factors contributing to intellectual impairment in a cohort of Japanese children with very low birth weight

Osamu UEMURA 1, 2 , Yukiyo NAGAI 3, Yuko MIZUTANI 2, Tetsuji KANEKO 4, Takeshi SAHASHI 5, Ayako FUKUMOTO 1, Nana UEDA 6, Mari KOTSUKA 7, Ayumi ITOH 7, Manaka HATANAKA 7, Kanji YASUDA 1

1 Department of Pediatrics, Ichinomiya Medical Treatment & Habilitation Center, Ichinomiya, Japan; 2 Department of Neonatology and Pediatrics, Nagoya City University Graduate School of Medical Sciences, Nagoya City, Japan; 3 Department of Pediatrics, Japanese Red Cross Aichi Medical Center Nagoya Daini Hospital, Aichi, Japan; 4 Department of Clinical Research, Tokyo Metropolitan Children’s Medical Center, Tokyo, Japan; 5 Department of Pediatrics, Ichinomiya Municipal Hospital, Ichinomiya, Japan; 6 Department of Clinical Psychology, Ichinomiya Medical Treatment & Habilitation Center, Ichinomiya, Japan; 7 Department of Rehabilitation, Ichinomiya Medical Treatment & Habilitation Center, Ichinomiya, Japan


BACKGROUND: To determine whether prematurity, intrauterine growth restriction (IUGR), or neonatal stress affects intellectual impairment in children with very low birth weight (VLBW).
METHODS: This national historical cohort study evaluated children with VLBW cared for in perinatal medical centers throughout Japan. Factors assessed included three latent variables (prematurity, IUGR, and stress during the neonatal period) and eight observed variables during perinatal period. The primary endpoint was intellectual or developmental quotient (IQ/DQ) at age ≥3 years. Structural equation model (SEM) was used to examine factors associated with IQ/DQ.
RESULTS: The study included 248 VLBW children, who were of mean age 5.7±2.0 years and mean IQ/DQ of 85.5 at last encounter. SEM showed that stress during the neonatal period (β=-0.37) contributed more to IQ/DQ than intrauterine malnutrition (β=0.25) and prematurity (β=0.15) and that the duration of mechanical ventilation was an important contributor to stress during the neonatal period.
CONCLUSIONS: Neonatal stress was more harmful to future intellectual impairment of VLBW neonates, with IUGR contributing more than prematurity. Duration of mechanical ventilation was an important risk factor in neonatal stress. Neonatologists should minimize neonatal stress in VLBW neonates, and obstetricians should monitor fetal growth restriction to prevent intellectual impairment in later life.

KEY WORDS: Intellectual impairment; Intelligence quotient; Intrauterine growth restriction; Mechanical ventilation; Very low birth weight

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