1996至2010年北京市活产新生儿出生体重变化趋势及其影响因素

目的 描述1996至2010年北京市新生儿出生体重变化趋势，并分析其影响因素。方法 采用病例回顾分析方法，选取北京妇产医院和北京市海淀区妇幼保健院1996、1997、1998、1999、2000、2005、2010出生的活产新生儿63 661例，描述1996至2010年低出生体重发生率变化趋势。以2010年北京妇产医院出生的活产新生儿11 006例为研究对象分析出生体重的影响因素。结果 1996至2010年，北京市新生儿出生体重变化趋势表现为2000年以前快速递增，2000年以后缓慢递减，2010年新生儿出生体重均值为3 331 g，高于2005年全国九城市儿童体格发育调查城市出生体重水平。多元回归分析显示，新生儿出生体重与产妇年龄、文化程度、孕前BMI、孕期增重、胎数、孕次、产次、早产、羊水量、新生儿性别、妊娠糖尿病和妊娠高血压均有相关性。结论 北京市新生儿出生体重变化趋势表现为2000年前快速递增，2000年后缓慢递减。应加强孕前保持正常BMI范围、控制孕期增重、避免早产、预防妊娠糖尿病和妊娠高血压的科普宣传教育。

Trends and determinants of birthweight among live births in Beijing, 1996-2010

Objective To describe and analyze the trends and determinants of birthweight in Beijing from 1996 to 2010.Methods 63 661 babies born in two hospitals in Beijing in 1996, 1997, 1998, 1999, 2000, 2005, 2010 were included to describe the trend of birthweight. The 11 006 birth records of those babies born in Beijing obstetric and gynecologic hospital in 2010 were collected to analyze the determinants of birthweight. The chi-square test and chi-square test for trend were used to estimate the distribution of categorical variables between groups, analysis of variance was used to test the difference of birthweight among years, linear regression analysis was applied to analyze the determinants of birthweight.Results The birthweight increased from 1996 to 2000 rapidly, and then decreased slowly. The mean value of birthweight in 2010 was 3 331 g, and it was higher than the national level. The linear regression analysis suggested that maternal age, body mass index, gestational weight gain, gravidity, parity, gestational weeks and gestational diabetes mellitus were positively correlated with birthweight, the gender of neonate （female）, degree of maternal education, oligohydramnios, multiple gestation and gestational hypertension were negatively associated with birthweight. According to the American Institution of Medicine （IOM） guidelines on maternal health weight gain, more than half of the women had excessive gestational weight gain from 2000.Conclusions The birthweight increased rapidly before 2000, and then decreased slowly. Maintaining a normal maternal body mass index and an appropriate gestational weight gain, avoiding preterm birth and prevention of gestational diabetes mellitus and hypertension will be helpful to get normal birthweight.