Deter Russell L, Lee Wesley, Sangi-Haghpeykar Haleh, Tarca Adi L, Yeo Lami, Romero Roberto
Department of Obstetrics and Gynecology, Baylor College of Medicine , Houston, TX , USA .
J Matern Fetal Neonatal Med. 2015 May;28(7):755-65. doi: 10.3109/14767058.2014.934219. Epub 2014 Jul 11.
To evaluate the impact of late 3rd trimester fetal growth cessation on anatomical birth characteristic predictions used in classifying SGA neonates.
A prospective longitudinal study was performed in 119 pregnancies with normal neonatal growth outcomes. Seven biometric parameters were measured at 3-4 weeks intervals using 3D ultrasonography. Rossavik size models were determined to predict birth characteristics at different ages. Percent Differences (% Diff) were calculated from predicted and measured birth characteristics. Growth Cessation Ages (GCA) were identified when no systematic change in % Diff values occurred after specified prediction ages. Systematic and random prediction errors were compared using different assumptions about the GCA. Predicted and measured size parameters were used to determine six new Growth Potential Realization Index (GPRI) reference ranges. Five were used to sub-classify 34 SGA neonates (weight < 10th percentile) based on the number of abnormal GPRI values.
Growth cessation ages were 38 weeks for HC, AC, mid-thigh circumference, estimated weight and mid-arm circumference. Crown-heel length GCA was 38.5 weeks. At GCA, birth characteristics had prediction errors that varied from 0.08 ± 3.4% to 15.7 ± 9.1% and zero % Diff slopes after 38 weeks. Assuming growth to delivery gave increased systematic and random prediction errors as well as positive % Diff slopes after 38 weeks, MA. Seventeen of the SGA neonates had 0 or 1 abnormal GPRI values [Subgroup 1] and 17 others had 2 or more abnormal values [Subgroup 2]. In Subgroup 1, 4/85 (4.7%) of GPRI's were abnormal while in Subgroup 2, 43/85 (50.6%) were abnormal. Use of only one type of GPRI for SGA subclassification resulted in substantial false negative and some false positive rates when compared to subclassification based on all five GPRI values.
Growth cessation occurred at approximately 38 weeks for all six birth characteristics studied. SGA neonates can be separated into normal and growth restricted subgroups based on the frequency of abnormal GPRI values (GPRI Profile Classification).
评估妊娠晚期胎儿生长停止对小于胎龄儿（SGA）新生儿分类中使用的解剖学出生特征预测的影响。
对119例新生儿生长结局正常的妊娠进行前瞻性纵向研究。使用三维超声每隔3 - 4周测量七个生物测量参数。确定Rossavik尺寸模型以预测不同孕周的出生特征。根据预测和测量的出生特征计算百分比差异（%Diff）。当在特定预测孕周后%Diff值没有系统性变化时，确定生长停止孕周（GCA）。使用关于GCA的不同假设比较系统预测误差和随机预测误差。使用预测和测量的尺寸参数确定六个新的生长潜能实现指数（GPRI）参考范围。其中五个用于根据异常GPRI值的数量对34例SGA新生儿（体重<第10百分位数）进行亚分类。
头围（HC）、腹围（AC）、大腿中部周长、估计体重和上臂中部周长的生长停止孕周为38周。顶臀长的GCA为38.5周。在GCA时，出生特征的预测误差在0.08±3.4%至15.7±9.1%之间变化，38周后%Diff斜率为零。假设生长持续至分娩会增加系统和随机预测误差，以及38周后出现正的%Diff斜率。17例SGA新生儿有0或1个异常GPRI值[亚组1]，另外17例有2个或更多异常值[亚组2]。在亚组1中，85个GPRI中有4个（4.7%）异常，而在亚组2中，85个中有43个（50.6%）异常。与基于所有五个GPRI值的亚分类相比，仅使用一种类型的GPRI进行SGA亚分类会导致大量假阴性和一些假阳性率。
所研究的所有六个出生特征的生长停止均发生在约38周。根据异常GPRI值的频率（GPRI轮廓分类），SGA新生儿可分为正常和生长受限亚组。
