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

doi:10.1212/CPJ.0000000000000920

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

Neurol Clin Pract. 2021 Oct;11(5):398-405. doi: 10.1212/CPJ.0000000000000920.

Authors

Michiko Torio¹, Mariko Iwayama¹, Toru Sawano¹, Hirosuke Inoue¹, Masayuki Ochiai¹, Ryoji Taira¹, Kousuke Yonemoto¹, Yuko Ichimiya¹, Yuri Sonoda¹, Momoko Sasazuki¹, Yoshito Ishizaki¹, Masafumi Sanefuji¹, Kenichi Yamane¹, Hiroshi Yamashita¹, Hiroyuki Torisu¹, Ryutaro Kira¹, Toshiro Hara¹, Shigenobu Kanba¹, Yasunari Sakai¹, Shouichi Ohga¹

Affiliation

¹ Department of Pediatrics (MT, MI, TS, HI, MO, RT, K. Yonemoto, Y. Ichimiya, Y. Sonoda, M. Sasazuki, Y. Ishizaki, M. Sanefuji, Y. Sakai, SO), Graduate School of Medical Sciences, Kyushu University, Fukuoka; Department of Health and Welfare (M. Sasazuki), Seinan Jogakuin University, Kitakyushu; Department of Neuropsychiatry (K. Yamane, HY, SK), Graduate School of Medical Sciences, Kyushu University, Fukuoka; Section of Pediatrics (HT), Department of Medicine, Fukuoka Dental College; and Fukuoka Children's Hospital (RK, TH), Japan.

Abstract

Objectives: To determine the neurodevelopmental outcomes of very-low-birth-weight infants (VLBWIs, birth weight <1,500 g) after 9 years of follow-up.

Methods: This 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.

Results: Neurodevelopmental 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.

Conclusion: These 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.