INTRODUCTION This study aimed to investigate the outcomes of infants at 18-24 months born in the Korean Neonatal Network with a birth weight <500 g. METHODS The anthropometric and neurodevelopmental data of infants with a birth weight <500 g at a gestational age of ≥22 weeks who were registered in the Korean Neonatal Network 2013-2017 and followed up at a corrected age of 18-24 months were reviewed. Neurodevelopmental impairment was defined as the presence of any of the following: (1) cerebral palsy; (2) severe visual impairment; (3) hearing impairment; or (4) cognitive impairment. Cognitive impairment was defined as (1) a Bayley Scales of Infant Development-II Mental Development Index score <70; and (2) Bayley Scales of Infant and Toddler Development-III Cognitive and Language Composite scores <85. Cognitive testing was performed for infants with suspected problems upon clinician's referral to developmental specialists. RESULTS At a median corrected age of 20 months, 26/52 (50%) of included infants had neurodevelopmental impairment. Cerebral palsy, severe visual impairment, wearing of glasses, hearing impairment, and cognitive impairment occurred in 22%, 0%, 8%, 5%, and 57% of the included infants, respectively. The proportions of infants with <2 standard deviations of weight, length, and head circumference were 54%, 52%, and 56%, respectively. The majority (70%) of infants were rehospitalized, and the most common cause was respiratory problems. CONCLUSION Half of infants with a birth weight <500 g in Korea may exhibit neurodevelopmental impairment and growth retardation at a corrected age of 18-24 months. Multidisciplinary follow-up along with continuous rehabilitation will be needed to improve neurological and physical development in this special population.

中文翻译：

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2013-2017 年韩国出生的出生体重低于 500 克的婴儿 18-24 个月的结果：全国队列研究。

简介 本研究旨在调查韩国新生儿网络中出生体重 <500 克的 18-24 个月婴儿的结局。方法 对 2013-2017 年在韩国新生儿网络登记并在 18-24 个月的校正月龄进行随访的出生体重 <500 g、胎龄≥22 周的婴儿的人体测量和神经发育数据进行回顾。神经发育障碍定义为存在以下任何一种情况：（1）脑瘫；(2)严重视力障碍；(3)听力障碍；(4) 认知障碍。认知障碍定义为（1）贝利婴儿发展量表-II心理发展指数得分<70；(2) 贝利婴幼儿发展量表-III 认知和语言综合得分<85。临床医生将其转诊给发育专家后，对疑似有问题的婴儿进行了认知测试。结果 在中位校正年龄为 20 个月时，26/52 (50%) 的纳入婴儿患有神经发育障碍。所纳入的婴儿中，脑瘫、严重视力障碍、戴眼镜、听力障碍和认知障碍的发生率分别为 22%、0%、8%、5% 和 57%。体重、身长和头围<2个标准差的婴儿比例分别为54%、52%和56%。大多数（70%）婴儿再次住院，最常见的原因是呼吸系统问题。结论 在韩国，一半出生体重<500 g的婴儿在18-24个月的校正年龄时可能表现出神经发育障碍和生长迟缓。需要多学科随访和持续康复来改善这一特殊人群的神经和身体发育。