太原市新生儿的胎龄相关出生体重分布

目的：构建当地出生体重分布曲线，为临床诊断、流行病学研究和公共卫生决策提供科学依据。方法出生数据来自于太原市出生监测系统，2006-2011年最终符合分析质量要求的单胎、活产儿共计227083例。通过末次月经与分娩日期计算所得胎龄与 B 超诊断胎龄比较，提高胎龄估计的准确性。采用两个高斯分布混合模型鉴别主要分布，应用局部加权回归散点平滑法拟合光滑曲线。结果新生儿出生体重值提供了生物学上合理的平均值、标准差和百分位数值，同时提供了更光滑的百分位数曲线；与以往研究相比，胎龄两端，尤其是小胎龄段，数值趋于稳定；与其它国家的参考值相比，太原的体重值低于欧美研究，与亚洲国家接近。结论基于最新出生人口信息、分性别构建的出生体重分布曲线为新生儿健康状况评价、时空分布和干预措施实施提供参考依据。

A new and improved population-based reference for gestation-specific birthweight in Taiyuan city

Objective To develop a local fetal growth curve that can be used as a reference by clinicians, researchers and public health policy makers. Methods We used data of singleton births between 2006 and 2011 from the Taiyuan Birth Surveillance System.Information on gestational age based on ultrasound estimates was available for 82.86% of the newborns.Gestational age calculated through the first day of last menstrual period and birth date was compared with ultrasound-estimated age to improve the estimate validity and reliability.Two-component Gaussian Mixture Models was used to identify the major distribution,and locally weighted scatter plot smoothing was used to smooth the curve. Results The resulting male and female curves provided smooth and biologically plausible means,standard deviations,and percentile cutoffs.The reference at low and high gestational ages was considerably robust than our previous reference.Compared with studies from other parts of the world,our reference was lower than those from the European and North America countries,but close to those from Asian countries. Conclusion This new sex-specific,population-based reference may help improve clinical assessment of growth in individual newborns,population-based surveillance of geographic and temporal trends in birth weight by gestational age,and evaluation of clinical or public health interventions that maim to enhance fetal growth.