MOE and Shanghai Key Laboratory of Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine and School of Public Health, Shanghai, China.
Paediatr Perinat Epidemiol. 2012 May;26(3):199-207. doi: 10.1111/j.1365-3016.2012.01261.x. Epub 2012 Feb 10.
Predicting large fetuses at birth has long been a challenge in obstetric practice. We examined whether ultrasound examinations at multiple times during pregnancy improve the accuracy of prediction using repeated, longitudinal statistical modelling, and whether adding maternal characteristics improves the accuracy of prediction. We used data from a previous study conducted in Norway and Sweden from 1986 to 1989 in which each pregnant woman had four ultrasound examinations at around 17, 25, 33 and 37 weeks of gestation. At birth, infant size was classified as large-for-gestational age (LGA, >90th centile) and macrosomia (>4000 g) or not. We used a longitudinal random effects model with quadratic fixed and random effects to predict term LGA and macrosomia at birth. Receiver-operator curves and mean-squared error were used to measure accuracy of the prediction. Ultrasound examination around 37 weeks had the best accuracy in predicting LGA and macrosomia at birth. Adding multiple ultrasound examinations at earlier gestations did not improve the accuracy. Adjusting for maternal characteristics had limited impact on the accuracy of prediction. Thus, a single ultrasound examination at late gestation close to birth is the simplest method currently available to predict LGA and macrosomia.
预测胎儿出生时的大小一直是产科实践中的一个挑战。我们研究了在多次怀孕期间进行超声检查是否通过重复的纵向统计建模提高预测的准确性，以及是否添加产妇特征可以提高预测的准确性。我们使用了来自挪威和瑞典在 1986 年至 1989 年期间进行的一项先前研究的数据，在该研究中，每位孕妇在妊娠约 17、25、33 和 37 周时进行了四次超声检查。在出生时，婴儿的大小被分类为大于胎龄儿（LGA，>第 90 百分位）和巨大儿（>4000 克）或不是。我们使用具有二次固定和随机效应的纵向随机效应模型来预测足月 LGA 和巨大儿。接收者操作曲线和均方误差用于衡量预测的准确性。在 37 周左右的超声检查对预测足月 LGA 和巨大儿具有最佳的准确性。在早期妊娠时添加多次超声检查并不能提高准确性。调整产妇特征对预测的准确性影响有限。因此，在接近分娩时进行单次超声检查是目前预测 LGA 和巨大儿的最简单方法。
