Fetal Echocardiographic Measurements of Aortic Arch between 20 and 38 Gestational Weeks: Normative Data for Various Fetal Growth Parameters

Lim, Kyoung Ah; Kim, Ki Eun; Kim, Myung Seon; Hong, Su Kyoung; Jung, Yun Hwa

Abstract

PURPOSE
Assessment of the diameters of the aortic arches in the human fetus may be helpful in the prenatal diagnosis of aortic arch anomalies. The purpose of this study is to construct valuable reference ranges of fetal aortic arch for various fetal growth parameters in an unselected Korean population.
METHODS
A prospective, cross-sectional study was performed in 98 normal singleton fetuses between 20 and 38 weeks of gestation. The transverse aortic arch diameter (TAD) and distal aorta isthmus diameter (AID) were measured in the longitudinal view during systole. The bi-parietal diameter (BPD), head circumference (HC), abdominal circumference (AC) and femur length (FL) were obtained at the same time. Ultrasound examinations were performed with a 2.0-6.0 MHz convex probe by abdominal ultrasound.
RESULTS
TAD and AID as a function of gestational age (GA) was expressed by the regression equation TAD= -1.246+0.168 X GA, and AID = -1.341+0.180 X GA; TAD and AID are expressed in millimeters and GA in weeks. TAD and AID as a function of BPD was expressed by the regression equation TAD= -1.147+0.664 X BPD, and AID = -1.152+0.696 X BPD. TAD and AID as a function of HC was expressed by the regression equation TAD = -1.187+0.182 X HC, and AID = -1.350+0.198 X HC. TAD and AID as a function of AC was expressed by the regression equation TAD = -0.528+0.173 X AC, and AID = -0.533+0.183 X AC. TAD and AID as a function of FL was expressed by the regression equation TAD = -0.519+0.799 X FL, and AID = -0.601+0.860 X FL; BPD, HC, AC and FL are expressed in centimeters. Correlations were found to be highly statistically significant in relation to GA, BPD, HC, AC, and FL respectively (P<0.0001 in all). Normal mean of TAD and AID per GA, BPD, HC, AC and FL and 95% prediction limits were also defined, respectively.
CONCLUSION
New reference ranges of fetal aortic arch related to other fetal bio-parameters representing fetal growth were obtained successfully. The normative date will be helpful in the prenatal accurate diagnosis of aortic anomalies and abnormal growth of fetal aortic arches in Korea.