Université Paris Sud, Maternité, CHU Antoine Béclère, AP-HP, Clamart, France.
Prenat Diagn. 2010 Jan;30(1):40-2. doi: 10.1002/pd.2417.
To compare retrospectively the distribution of foetal biometry data as measured by midwives and physicians during second and third trimester screening of an unselected population of pregnant women.
Standard measurements of biparietal diameter (BPD), head circumference (HC), abdominal circumference (AC), and femur length (FL) were performed by four midwives and ten physicians at 20 to 24 weeks of gestation and at 30 to 34 weeks of gestation as part of routine ultrasound examinations over a 26-month period (Jan. 2005-Mar. 2007). All measurements were converted into Z-scores using different prediction equations. The reference chart best fitting our practice was determined for each fetal parameter (French College of Sonographers for BPD, Chitty et al. for HC and FL, Snidjers and Nicolaides for AC). The means and SDs of the Z-score distributions for data collected by midwives and physicians were compared using Student's t-test for means and the Fisher-Snedecor test for SDs.
We retrieved 1566 and 1631 measurements made by midwives and physicians respectively between 20 and 24 weeks of gestation, and 1710 and 1578 measurements made by midwives and physicians respectively between 30 and 34 weeks of gestation. Mean values recorded by midwives were significantly closer to 0 (p < 0.05) for many foetal parameters. SD values were also significantly lower and were below 1.
In this study, midwives have a greater tendency than physicians to normalize biometry data. Such normalization may hamper the sensitivity of routine ultrasound screening for abnormal foetal growth.
回顾性比较在对未经选择的孕妇人群进行的二、三孕期筛查中，助产士和医生测量的胎儿生物测量数据分布情况。
在 26 个月的时间内（2005 年 1 月至 2007 年 3 月），4 名助产士和 10 名医生在 20-24 孕周和 30-34 孕周的常规超声检查中，对双顶径（BPD）、头围（HC）、腹围（AC）和股骨长（FL）进行了标准测量。所有测量值均使用不同的预测方程转换为 Z 评分。为每个胎儿参数确定了最适合我们实践的参考图表（法国超声学会用于 BPD，Chitty 等人用于 HC 和 FL，Snidjers 和 Nicolaides 用于 AC）。使用均值学生 t 检验和标准差 Fisher-Snedecor 检验比较了助产士和医生收集的数据的 Z 评分分布的均值和标准差。
我们分别检索了 20-24 孕周时助产士和医生测量的 1566 和 1631 次测量值，以及 30-34 孕周时助产士和医生测量的 1710 和 1578 次测量值。许多胎儿参数的记录均值更接近 0（p<0.05）。SD 值也显著降低且低于 1。
在这项研究中，与医生相比，助产士更倾向于将生物测量数据标准化。这种标准化可能会降低常规超声筛查异常胎儿生长的敏感性。
