Abstract Low birth weight infants (LBWI) are defined as newborn with birth weight less than 2500g, including preterm infants and small for date infants. Preterm infants are those with gestational age less than 37 weeks, whereas small for date infants are born with birth weight less than the 10th percentile of the normal value, or less than the mean minus 2 standard deviations. It is well known that the causes of LBWI are associated with maternal age, nutritional status, social economical factors, drug addiction, alcoholism, educational level, marital status, times of gestation and partum, irregular or without prenatal care, heavy physical labor work and diseases during pregnancy. It is also closely related to placental and fetal factors. LBWI have high perinatal morbidity and mortality. They are associated with different degrees of handicap in physical and mental development, learning, awareness and accommodation. They are more prone to develop chronic diseases in adulthood as compared to infants with normal birth weight. Due to progressive development in medical technology, the survival rate of LBWI is increasing. Being born with suboptimal health, LBWI have great impact on the quality of population. The problem of population quality and social burden caused by LBWI has aroused international attention in recent decades. There are different policies and interventions in different regions and countries according to their situations. The experience of interventions has been summarized in this paper, hoping to provide relevant information for the interested researchers and policy makers. Besides there is an increasing trend in the incidence of LBWI in Macau recently. A case- control retrospective study was conducted in this paper through file revision. There were total 252 mothers and their 267 newborns being born in Central Hospital of Conde de São Januário between 1st July 2006 and 30th June 2007 being investigated. Among them there were 151 LBWI and 116 normal birth weight infants. After analyzing the risk factors of LBWI by non-conditional logistic regression, followed by forward method of regression study, it showed that gestational age, maternal body weight, less prenatal care visits, oligohydramnios and intrauterine growth retardation were the maternal factors affecting the occurrence of LBWI. The smaller the gestational age is, the higher the risk of LBWI is. While the maternal body weight increases, the risk of LBWI decreases. The less the prenatal care visits are, the higher the risk of LBWI is. Oligohydramnios and intrauterine growth retardation being found prenatally increase the risk of LBWI. Therefore, the attention of the government and society on the prevention of LBWI, proper education, prenatal care, prevention and treatment of preterm labor, nutritional enrichment and treatment of the complications and diseases during pregnancy play an important role in the prevention of LWBI. Key Words: Low birth weight infants, risk factors, intervention

摘要 低出生體重兒是指出生時體重不足2500克的新生兒,包括早產兒和足月小於胎 齡兒。早產兒是指胎齡小於37週者,小於胎齡兒是指出生體重在該胎齡體重正常 值的第10百分位以下或小於均值減去2個標準差,也稱宮內發育遲緩。 低出生體重兒的發生與母親的年齡、營養狀況、社會經濟因素、嗜藥、吸煙、 飲酒、教育水平、婚姻狀況、妊產次、不規律或沒有產前檢查、孕期重體力勞動 及懷孕期的疾病等有關;也與胎盤因素及胎兒因素等有密切關係。 低出生體重兒有較高的圍產期發病率和死亡率,生長發育、智能發展、學習、 認知及適應性均出現不同程度的障礙,成年以後比正常出生體重兒更容易患各種 慢性疾病。隨著醫學技術的不斷提高,低出生體重兒的存活率不斷上升,低出生 體重兒作為亞健康出生的兒童,對人口質素有不可輕視的影響。 目前國際社會高度重視低出生體重兒給人口質量以及社會負擔引起的問題,而 不同的國家、地區因應國情的不同,均有不同的政策和監控措施,本文總結了多 個國家的監控經驗,希望能為有研究興趣的學者和政策制定者提供參考。 此外,結合澳門低出生體重兒發生率似有上升的趨勢,本文以病歷查閱作回顧 性的分析,調查了252名母親及其於2006年7月1日~2007年6月30日在澳門仁伯爵綜 合醫院出生的新生兒267名,其中低出生體重兒151名,116名體重正常兒。並將 低出生體重兒發生的重要因素,以新生兒低體重與否作為結局變量進行單因素非 條件回歸分析,跟據非條件Logistic 單因素回歸分析結果,採用逐步引入的方法, 把作用顯著的因素按其大小依次引入回歸方程,直至作用不顯著為止,結果示孕 週、母親的體重、產前檢查次數少和合并羊水過少及宮內發育遲緩是影響新生兒 低出生體重兒發生的母親因素。孕週越小,低出生體重兒的發生危險性增加。隨 着母親的體重增加,低出生體重兒的發生危險性下降。產前檢查次數少,低出生 體重兒的發生危險性增加,產前檢查發現羊水過少及宮內發育遲緩,低出生體重 兒的發生危險性增加。 因此,政府、社會各界重視防治低出生體重兒,加强宣傳教育,重視產前檢查, iv 澳門大學碩士學位論文 防治早產,加强孕期的營養,積極治療懷孕期的各種並發症和合并症,對降低低 出生體重兒的發生有重要意義。 關鍵詞:低出生體重兒,影響因素,幹預