Reddy Ramireddy Harikiran, Prashanth Kumar, Ajit Mahale
Assistant Professor, Department of Radiology, JJM Medical College, Davangere, Karnataka, India.
Professor, Department of Radiology, A J Shetty Medical College, Mangalore, Karnataka, India.
J Clin Diagn Res. 2017 Jun;11(6):TC01-TC04. doi: 10.7860/JCDR/2017/23583.9968. Epub 2017 Jun 1.
The most important parameter needed for appropriate management of pregnant women is accurate Gestational Age (GA). Routine sonographic estimation of GA by using Biparietal Diameter (BPD), Femur Length (FL), Abdominal Circumference (AC) and Head Circumference (HC) assumed important role in management of pregnancy. However, these parameters have limitations. BPD and HC are not reliable in case of moulding of foetal head in third trimester. Similarly, femur length is shortened in cases of achondroplasia. Transcerebellar Diameter (TCD) was developed as an alternative parameter of foetal brain growth and for estimation of GA.
To evaluate accuracy of predicting GA using Foetal Transcerebellar Diameter (TCD) and to compare between TCD and other existing parameters in evaluating GA in 15 to 40 weeks of gestation.
A prospective study was carried out in 100 pregnant women between 15 to 40 weeks of gestation, who came for routine antenatal sonography. Transcerebellar diameter was measured along with routine parameters. Subjects were divided into two groups based on GA (15-28 and 29-40 weeks). Gestational age using TCD and other parameters was calculated and compared with gestational age based on Last Menstrual Period (LMP). Correlation between the GA by LMP with GA by other ultrasound parameters was done by using Karl Pearson's Correlation(r).
In 15-28 weeks, all parameters had nearly equal r-values. Among all parameters, TCD revealed highest correlation with value of 0.997. In 29-40 weeks, there was considerable difference in r-values. An r-value of 0.982 was noted, when the GA by TCD and LMP was compared, r-value of which is more than the other parameters. The least correlation was seen with BPD, r=0.951. The second most accurate correlation was seen with the FL with r-value of 0.981.
TCD is an accurate parameter in estimation of gestational age in second and third trimesters as its values are in close relation with that of GA by LMP. It is also better predictor of the gestational age when compared to other parameters especially in third trimester.
对孕妇进行恰当管理所需的最重要参数是准确的孕周（GA）。通过双顶径（BPD）、股骨长度（FL）、腹围（AC）和头围（HC）进行孕周的常规超声估测在孕期管理中发挥着重要作用。然而，这些参数存在局限性。在孕晚期胎儿头部塑形的情况下，BPD和HC不可靠。同样，在软骨发育不全的病例中股骨长度会缩短。小脑横径（TCD）作为胎儿脑生长的替代参数及孕周估测方法而被开发出来。
评估使用胎儿小脑横径（TCD）预测孕周的准确性，并在孕15至40周评估GA时比较TCD与其他现有参数。
对100名孕15至40周前来进行常规产前超声检查的孕妇进行了一项前瞻性研究。测量了小脑横径以及常规参数。根据孕周（15 - 28周和29 - 40周）将受试者分为两组。计算使用TCD和其他参数得出的孕周，并与基于末次月经日期（LMP）的孕周进行比较。使用卡尔·皮尔逊相关性（r）分析LMP得出的孕周与其他超声参数得出的孕周之间的相关性。
在15 - 28周时，所有参数的r值几乎相等。在所有参数中，TCD显示出最高的相关性，值为0.997。在29 - 40周时，r值存在相当大的差异。比较TCD和LMP得出的孕周时，r值为0.982，该值高于其他参数。与BPD的相关性最低，r = 0.951。与FL的相关性次之，r值为0.981。
TCD是孕中期和孕晚期孕周估测的准确参数，因为其值与LMP得出的孕周密切相关。与其他参数相比，它也是更好的孕周预测指标，尤其是在孕晚期。
