Neurodevelopmental Outcomes of High-Risk Preterm Infants: A Prospective Study in Japan

Michiko Torio, Mariko Iwayama, Toru Sawano, Hirosuke Inoue, Masayuki Ochiai, Ryoji Taira, Kousuke Yonemoto, Yuko Ichimiya, Yuri Sonoda, Momoko Sasazuki, Yoshito Ishizaki, Masafumi Sanefuji, Kenichi Yamane, Hiroshi Yamashita, Hiroyuki Torisu, Ryutaro Kira, Toshiro Hara, Shigenobu Kanba, Yasunari Sakai, Shouichi Ohga

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


ObjectivesTo determine the neurodevelopmental outcomes of very-low-birth-weight infants (VLBWIs, birth weight <1,500 g) after 9 years of follow-up.MethodsThis study prospectively recruited 224 VLBWIs born from 2003 to 2009 in Kyushu University Hospital, Japan. Comorbidities of neurocognitive impairment, epilepsy, and autism spectrum disorder or attention-deficit hyperactivity disorder (ASD/ADHD) were assessed at age 3, 6, and 9 years.ResultsNeurodevelopmental profiles were obtained from 185 (83%), 150 (67%), and 119 (53%) participants at age 3, 6, and 9 years, respectively. At age 9 years, 25 (21%) VLBWIs showed intelligence quotient (IQ) <70, 11 (9%) developed epilepsy, and 14 (12%) had a diagnosis of ASD/ADHD. The prevalence of epilepsy was higher in children with an IQ <70 at age 9 years than in those with an IQ ≥70 (44% vs 0%). In contrast, ASD/ADHD appeared at similar frequencies in children with an IQ <70 (16%) and ≥70 (11%). Perinatal complications and severe brain lesions on MRI were considered common perinatal risks for developmental delay and epilepsy but not for ASD/ADHD. Male sex was identified as a unique risk factor for ASD/ADHD.ConclusionThese data suggest that VLBWIs showed a higher prevalence of developmental delay, epilepsy, and ASD/ADHD at age 9 years than the general population. Distinct mechanisms might be involved in the pathogenic process of ASD/ADHD from those of developmental delay and epilepsy.

Original languageEnglish
Pages (from-to)398-405
Number of pages8
JournalNeurology: Clinical Practice
Issue number5
Publication statusPublished - Oct 1 2021

All Science Journal Classification (ASJC) codes

  • Clinical Neurology


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