日本新生児成育医学会雑誌　37(2)：111-117；2025　

日本新生児成育医学会雑誌　第37巻　第2号　111 ～ 117頁（2025年）

受付日：2024．12．27

受理日：2025．04．28

在胎23 ～ 25 週で出生した「早生まれ児」の発達と就学状況

Developmental Outcomes of Preterm Infants Born at 23 ～ 25 Weeks Gestation：Impact of Early Enrollment in School

＊ 1 神奈川県立こども医療センター　新生児科，＊ 2 川崎市北部地域療育センター

＊ 1 Department of Neonatology, Kanagawa Children’s Medical Center， ＊ 2 Kawasaki-North Ryouiku Center

野口聡子＊ 1・豊島勝昭＊ 1・下風朋章＊ 1・山口直人＊ 1 ＊ 2・齋藤朋子＊ 1・柴崎　淳＊ 1・星野陸夫＊ 1

Satoko NOGUCHI ＊ 1，Katsuaki TOYOSHIMA ＊ 1，Tomoaki SHIMOKAZE ＊ 1，Naoto YAMAGUCHI ＊ 1 ＊ 2， Tomoko SAITO ＊ 1，Jun SHIBASAKI ＊ 1，Rikuo HOSHINO ＊ 1

Key Words：extremely preterm，developmental outcome，early school entry，educational support

早産によって予定日出生より小学校入学が1 年早くなる場合に，保護者が不安を訴えることがある。2002 年4 月 から2011 年3 月出生の在胎23 ～ 25 週の児59 名のうち予定日では翌年度入学となる19 名を早生まれ，それ以外 の40 名を非早生まれとし発達や就学状況を後方視的に検討した。修正1 歳半，3 歳の新版K 式発達検査2001 全領 域DQ に差がなかったが，Wechsler 式知能検査全検査IQ は6 歳88±13（早生まれ），76±18（非早生まれ）（p＜ 0.01），9 歳91±16（早生まれ），77±19（非早生まれ）（p＜0.01）と早生まれ群で高かった。通常学級は入学時74 ％（早生まれ），70％（非早生まれ），小3 時69％（早生まれ），52％（非早生まれ）であった。早生まれ群の37％ は6 歳から9 歳でIQ が上昇し，就学により発達が促された可能性がある。早生まれのみを理由とした就学猶予は 慎重に判断すべきである。

In Japan, children enter primary school on April 1 after turning six. Depending on the gestational age and birth month, preterm children may begin primary school a year earlier than expected on the due date. Some parents of preterm children are anxious about their children entering school and consider school deferring. This study retrospectively examined the development and school support needs of 59 children born prematurely at 23 ～ 25 weeks of gestation between April 2002 and March 2011. Nineteen children who entered school a year earlier because of preterm birth were defined as “the early school entry group,” whereas 40 children whose enrollment year did not change because of premature birth were defined as “the on-schedule school entry group.” Developmental outcomes assessed at modified 18 months and three years using the Kyoto-scale of Psychological Development for children did not differ between the two groups. However, the mean full scale IQ score measured using Wechsler Intelligence Scale for Children at six and nine years old was higher in the early school entry group. For six-years-olds, the mean IQ was 88±13（ early entry group） and 76±18（ on-schedule entry group）, and for 9-years-olds, it was 91±16 （early entry group） and, 77±19 （on-schedule entry group）. The percentage of children in regular classes with no educational support at school entry was 74％ for the early entry group and 70％ in the on-schedule entry group. Additional educational support was needed up to the third grade for 7％ and 28 ％ of the early entry group and on-schedule entry group, respectively. After school enrollment, 37％ of the early school entry group had a further increase in IQ by age nine. Enrollment in school may have a positive impact on children’s development. Hence, the necessity of school deferment for preterm children must be carefully evaluated.