目標：出生體重1,500公克以下的極低出生體重早產兒是發展遲緩的高危險群。研究目的在探討2歲追蹤結果對於5歲長期發展預後的預測。方法：本回溯性研究以2001-2005年出生的極低出生體重早產兒為對象，資料取自二十一家合約醫院登錄在台灣早產兒基金會聯合追蹤小組資料庫。資料收集含括：出生狀況、新生兒罹病情形、家庭背景、父母社經地位、教育程度；2歲貝氏嬰兒發展量表（Bayley Scales of Infant Development Second Edition, BSID-Ⅱ）評估心智發展指數（mental development index, MDI）、動作發展指數（psychomotor development index,PDI）；5歲魏氏量表（Wechsler Preschool and Primary Scale of Intelligence-Revised, WPPSI-R）評估全量表智商（full scale intelligence quotient, FSIQ）指數等。並以多元邏輯斯回歸統計分析，探討影響5歲發展預後之預測因子。結果：940位早產兒中，111位（11.8%）2歲時心智發展正常（MDI≧85），5歲時心智發展遲緩（FSIQ＜85）。2歲MDI、PDI＜85、5分鐘ApgarScore＜6分、父親低學歷、出生體重≦1,000克及母親低社經地位等，是影響5歲心智輕微發展遲緩的重要因子（達統計顯著差異）。結論：極低出生體重早產兒2歲時發展雖然正常，但5歲時卻可能成為發展遲緩的高危險群。建議所有早產兒應追蹤直到5歲，並提供發展遲緩的孩子早期療育。

Objectives: Preterm infants with a birth weight ＜ 1,500 gm (very low birth weight [VLBW]) are a high-risk group for developmental delay. The purpose of this study was to determine the predictors of 5-year developmental outcomes in VLBW preterm infants based on the 2-year follow-up evaluation. Methods: All VLBW preterm infants were retrospectively recruited in this study between 2001 and 2005 using a large population-based cohort of VLBW infants from 21 neonatology departments registered in the database of the Premature Baby Foundation of Taiwan. Data, including condition at birth, socioeconomic status, educational level, family background, and neonatal morbidities, were collected. The mental development index (MDI) and psychomotor development index (PDI) were determined according to the second edition of the Bayley Scales of Infant Development (BSID-II) at 2 years of age. Also, the full scale intelligence quotient (FSIQ) was determined according to the Wechsler Preschool and Primary Scale of Intelligence-Revised (WPPSI-R) at 5 years of age. Multiple logistic regression was used to identify the predictors of 5-year outcomes. Results: Among 940 VLBW preterm infants, 111 (11.8%) had normal development (MDI ＞ 85) at 2 years of age, but developmental delay (FSIQ ＜ 85) at 5 years of age. A MDI ＜ 85, PDI ＜ 85, APGAR score ＜ 6 at 5 min, birth weight ≤ 1,000 g, father with a low education level, or a mother with a low socioeconomic status were significant predictors of developmental outcomes at 5 years of age. Conclusions: VLBW preterm infants may have normal development at 2 years of age; however, VLBW preterm infants are also a high-risk group for developmental delay at 5 years of age. Thus, all VLBW infants should be followed until 5 years of age. Early intervention for developmental delay children is necessary.