All issues > Volume 35(11); 1992

Original Article

J Korean Pediatr Soc. 1992;35(11):1566-1572. Published online November 15, 1992.

Quantitative Assessment of the Diameters of Tricuspid Valve, Mitral Valve and Great Arteries in the Normal Human Fetus -Cross Sectional Echocardiographic Study-

Jung Yun JY Choi¹, Kyung Hee KH Park¹, Chung Il CI Noh¹, Yong Soo YS Yun¹, I Seok IS Kang¹, Eun Sook ES Han²

¹Department of Pediatrics, Seoul National University Children`s Hospital, Seoul, Korea
<sup>2</sup>Department of Echocardiographic Laboratory, Seoul National University Children`s Hospital, Seoul, Korea

Abstract

In order to assess the growth of the mitral valve, tricuspid valve, and the aortic and pulmonary pathways in the normal human fetus, 181 fetal echocardiograms taken from 127 pregnant women (some women had repeated examinations) were analysed. Diameters were measured from cross sectional images and were correlated with gestational period. The diameter ratios of tricuspid valve/mitral valve, aorta/main pulmonary artery, and various pairs of vascular sites were calculated only when the two sites for comparison were obtained in the same examination. These ratios were correlated with gestational period to see if these ratios changed with increasing gestational period. The diameters of each site increased linearly from gestational period of 15 weeks to 40 weeks. The diameter ratio of tricuspid/mitral valve was 1.07¡¾0.13 and did not show any changes with fetal growth. The diameter ratio of main pulmonary artery/aorta increased slightly from 1.13 at gestational age of 15 weeks to 1.31 at gestational age of 40 weeks. The diameter ratio of main pulmonary artery/arterial duct was 1.84¡¾0.20 and the ratio of main pulmonary artery/branch pulmonary artery was 2.32¡¾0.26 and the ratio of ductus arteriosus/branch pulmonary artery was 1.28¡¾0.18 and these ratios were not significant when compared to fetal growth. This study confirms the right ventricular dominance in the human fetus like the result of animal fetal study. However, in the human fetus, the relative size of branch pulmonary artery was bigger and relative size of ductus arteriosus was smaller than the results obtained from animal studies. Further study is necessary to determine flow distribution in the human fetus.

Keywords :Fetus, Heart, Cross-sectional Echocardiography