日本新生児成育医学会雑誌　第28巻　第1号　55～ 64頁（2016年）

日本新生児成育医学会雑誌 28(1)：55-64；2016　

受付日：平成27．01．08

受理日：平成27．09．04

早期経腸栄養主体の管理を行った極低出生体重児における身体発育の検討
―第一報：NICU 入院中のz スコアの推移と子宮外発育制限（EUGR）の発症率について―

Serial Evaluation of Physical Growth until Term Gestation by Using a z Score in Very Low Birth Weight Infants

国立病院機構佐賀病院総合周産期母子医療センター　小児科

Department of Pediatrics, National Hospital Organization Saga National Hospital

江頭智子・江頭政和・井上博晴・水上朋子・高柳俊光

Tomoko EGASHIRA，Masakazu EGASHIRA，Hiroharu INOUE，Tomoko MIZUKAMI，Toshimitsu TAKAYANAGI

Key Words：extrauterine growth restriction，very low birth weight infants，enteral nutrition，z score

　主として経腸栄養のみで栄養管理を行った極低出生体重児のNICU 入院中の体重と頭囲のZ スコアの推移と子宮外発育制限（EUGR）の発症率を検討した。対象は生存退院し日齢14 までに経腸栄養量が100mL/kg/ 日に到達した387 名で，出生体重10 パーセンタイル以上のA 群（n＝275，27.3±2.3 週，1,029±286g）と10 パーセンタイル未満のL 群（n＝112，28.4±1.8 週，783±215g）に分類した。その結果，体重EUGR の発症率はA 群で49％，L 群で90％，頭囲EUGR の発症率はA 群で2.2％，L 群で14.4％であった。体重は両群とも在胎週数が長じるに伴いEUGR 率は減じる傾向にあり，A 群では在胎24 週以降は約1/3，27 週以降は約2/3 の児がEUGR から脱却できていたが，L 群はいずれの週数も脱却は難しく，特に28 週未満は全例がEUGR 児であった。一方，頭囲は在胎週数にかかわらず，両群とも修正35 週以降のキャッチアップが急峻であった。頭囲と体重の出生後の成長の軌跡は異なり，現状の栄養管理では体重のEUGR の脱却は困難であることが示唆された。

Objective：The aim of the present study was to evaluate the incidence of extra uterine growth restriction （EUGR） in very low birth weight infants（ VLBWI） at a gestational age of ≦30 wks who were exclusively nourished by early enteral feeding.
Subjects and methods：The study subjects included 387 VLBWI divided into two groups depending on whether birth weight percentile was ≧10％；Group A（ n＝275, 27.3±2.3 wks, 1,029±286 g）, or ＜10％：Group L（ n＝112, 28.4±1.8 wks,783±215 g）. All subjects reached their feeding volume of ≧100 mL/kg/day within 14 days after birth. The rate of EUGR depending on body weight and head circumference was also evaluated for each group. In addition, the z score for body weight and head circumference in all subjects was calculated to clarify the growth velocity from birth to 40 wks after gestation by week.
Results：The rate of EUGR based on body weight in group A was 49％, which tended to increase with younger gestational age, approximately 30 to 40％ in subjects ≧27 wks, 60 to 70％ in subjects 24 to 26 wks, and ≧90％ in subjects 22 to 23 wks old. The rate of EUGR based on body weight in group L was 90％ , and all were diagnosed with EUGR at a gestational age of ＜28 wks. On the other hand, the incidence of EUGR based on head circumference was 2.2％ in group A and 14.4％ in group L. The growth trajectory based on head circumference revealed that this catch up is apparently observed beyond 35 wks, except in extremely premature infants at a gestational age of ＜24 wks.
Conclusion：Although the EUGR rate based on head circumference is relatively low, it is difficult to separate this from EUGR based on body weight in our nutritional protocol characterized as aggressive early enteral feeding.