Nelson L H
J Clin Ultrasound. 1981 Feb;9(2):67-70. doi: 10.1002/jcu.1870090205.
Determination of gestational age without an accurate last menstrual period is difficult. In the later stages of pregnancy, the correlation between fetal biparietal diameter (BPD), as determined by ultrasound, and gestational age is compromised by normal biologic variation in fetal growth rates. The fetal crown-rump measurement (CRM) by gray-scale sonography has been described but has not been evaluated using real-time ultrasound. Currently available tables for determining gestational age from the fetal CRM were evaluated using a linear array real-time ultrasound system. A normal obstetric population with known menstrual histories, delivery dates, and Dubowitz scores at delivery was used for evaluation. On the basis of this study, Robinson's data listed as "regression analysis values" are suggested for application to real-time ultrasound. Alternatively, the equation generated from data on the above 86 patients could be used and further evaluated. The fetal CRM appears to be a valid and accurate assessment of gestational age.
在没有准确末次月经日期的情况下，确定孕周很困难。在妊娠后期，超声测定的胎儿双顶径（BPD）与孕周之间的相关性会受到胎儿生长速率正常生物学变异的影响。已有文献描述了通过灰阶超声测量胎儿顶臀径（CRM），但尚未使用实时超声进行评估。本研究使用线性阵列实时超声系统评估了目前可用的根据胎儿CRM确定孕周的表格。选取了具有已知月经史、分娩日期及分娩时Dubowitz评分的正常产科人群进行评估。基于本研究，建议将Robinson列为“回归分析值”的数据应用于实时超声。或者，也可以使用根据上述86例患者数据生成的公式并进一步评估。胎儿CRM似乎是一种有效且准确的孕周评估方法。
