中文摘要：

目的：了解安徽省8地市小于胎龄儿（SGA）发生情况并分析其影响因素。方法：选择安徽省8地市妇幼保健部门首次保健服务的孕妇为研究对象，填写《孕产期母婴健康记录表》，收集母亲的社会人口统计学特征和孕前6个月及孕早期环境暴露因素，同时于孕晚期收集孕期妊娠期高血压等妊娠合并症及并发症的发生情况，记录单胎活产儿出生信息，运用X2检验和多因素Logistics回归模型分析人口统计学特征与环境暴露对SGA的影响。结果：SGA发生率为3．4％（357／10407），将SGA按重量指数分型，匀称型SGA占55．2％（197／357），非匀称型SGA占43．4％（155／357）；将SGA按身长／头围分型，为匀称型SGA占73．7％（263／357），非匀称型SGA占4．2％（15／357）。多因素Logistic回归模型结果显示，孕妇为城市户口、孕早期发生妊娠呕吐但未做医疗处理、孕期头3个月服用微量元素坚持1个月以上是SGA发生的保护因素，OR值分别为0．71（95％CI：0．57～0．89）、0．79（95％CI：0．63～0．99）、0．30（95％CI：0．11～0．81）；胎儿性别为女、孕前BMI〈18．5、发生妊娠呕吐并去医院就诊为SGA的危险因素，OR值分别为1．83（95％CI：1．47～2．29）、1．46（95％CI：1．16～1．85）、1．72（95％CI：1．12～2．65）。结论：孕妇孕前BMI较低及妊娠呕吐等会影响SGA的发生，加强孕前和孕期保健，应重视妊娠呕吐的发生，发生时应及时就诊以减少SGA的发生。

英文摘要：

Objective： To understand the prevalence of small for gestational age infants in 8 cities of Anhui province, analyze the effect factors. Methods： The pregnant women who received maternal health care for the first time in maternal and child health institutions of 8 cities in Anhui province were selected, and all of them were asked to finish maternal and infantile health records during pregnancy, the so- ciodemographic characteristics of pregnant women and environmental exposure factors during 6 months before pregnancy and the first trimester of pregnancy were collected, at the same time, the incidences of complications during pregnancy, such as hypertensive disorder complicating pregnancy （HDCP） , were calculated; the birth information of the neonates with single fetus and live birth were recorded. Chi - square analysis and multivariate logistic regression model were used to analyze the soeiodemographic characteristics of pregnant women and the effect of environmental exposure factors on small for gestational age infants. Results： The incidence of small for gestational age infants was 3.4% （357/10 407 ） , the small for gestational age infants were divided into different groups according to body mass index, the proportions of small for gestational age infants of symmetrical type and asymmetric type were 55.2% （197/357） and 43.4% （ 155/357 ）, respectively; the small for gestational age infants were divided into different groups according to body height/head circumference, the proportions of small for gestational age infants of symmetrical type and asymmetric type were 73.7% （263/357） and 4. 2% （15/357）, respectively. The results of muhivariate logistic regression model showed that urban registered permanent residence, vomiting during the first trimester of pregnancy and without any medical treatment, and taking trace elements for more than one month during the first trimester of pregnancy were the protective factors of small for gestational age infants, the OR values were 0.71 （ 95 % C