Abstract:
This was an observational study of low-risk singleton pregnancies in an ethnic Chinese population. Foetal biometric variables which included biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL) were measured repeatedly. The standard views for measurement were obtained according to INTERGROWTH-21st criteria. A linear mixed model with fractional polynomial regression was used to describe the longitudinal design. The study included 1289 foetuses and a total of 5125 ultrasound scans, of which each foetus was scanned at least three times, the intervals between scans being at least two weeks. The parameters of the linear mixed models were estimated by Stata v.16 (College Station, TX). Using these parameters, the equations of the mean and variance for BPD, HC, AC and FL were constructed. The conditional percentiles or Z scores could be calculated based on the above equations and previous measurements of the same foetus. A spreadsheet was provided for implementation.Impact StatementWhat is already known on this subject? Longitudinal data derived from serial measurements are therefore appropriate for assessing both foetal size and foetal growth. At present, most reference charts of ethnic Chinese foetal biometry are derived from cross-sectional data, which can only assess foetal size.What do the results of this study add? In this study, we have constructed conditional standards for foetal biometry in an ethnic Chinese population and provided a spreadsheet for querying.What are the implications of these findings for clinical practice and/or further research? The conditional standards can be used to assess foetal growth in clinical practice. In the future, we hope that these foetal growth standards can be applied to determine whether abnormal growth increases the risk of adverse outcomes.
摘要:
这是一项针对华裔人群低风险单胎妊娠的观察性研究。胎儿生物特征变量,包括双顶直径(BPD),头围(HC),重复测量腹围(AC)和股骨长度(FL)。根据INTERGROWTH-21标准获得测量的标准观点。使用具有分数多项式回归的线性混合模型来描述纵向设计。这项研究包括1289个胎儿和总共5125个超声扫描,其中每个胎儿至少被扫描三次,扫描之间的间隔至少为两周。线性混合模型的参数由Statav.16估计(CollegeStation,TX)。使用这些参数,BPD的均值和方差方程,HC,构建AC和FL。条件百分位数或Z分数可以基于上述等式和相同胎儿的先前测量来计算。提供了一个电子表格以供实施。因此,从连续测量得出的纵向数据适用于评估胎儿大小和胎儿生长。目前,大多数华裔胎儿生物特征的参考图表都来自横截面数据,只能评估胎儿的大小。这项研究的结果补充了什么?在这项研究中,我们已经为华裔人口的胎儿生物测量建立了有条件的标准,并提供了一个查询电子表格。这些发现对临床实践和/或进一步研究有什么意义?条件标准可用于评估临床实践中的胎儿生长。在未来,我们希望这些胎儿生长标准可用于确定异常生长是否会增加不良结局的风险。