Objective: To investigate the geometric shape of the ductus venosus between 10-13 weeks of gestation. Patients and methods: Ductus venosus measurements were performed in 64 normal human fetus using ultrasound color Doppler imaging. The geometrical measurements obtained were: length (n = 64), isthmic width (n = 34) and outlet width (n = 20). For statistical analysis, the analysis of variance, linear regression, Kruskal-Wallis terst and the Spearman correlation were used. Results: At 10-13 weeks of gestation, the ductus venosus length indicates a continuous growth and the width did not change. The measurements (median) were: length = 2 mm, isthimic inlet = 1.4 mm, and outlet width + 1.4 mm.
Conclusion:The new geometric shape of the ductus venosus between 10-13 weeks of gestation has a cylindrical and not a slender trumpet-like shape as defined previously in the literature. Objective: The objective of this study is to establish reference values for Dopplerfluxometric parameters of the ductus venosus (DV), in the period from 10 to 14 weeks of gestation in relation to blood velocities during ventricular contraction (S wave), ventricular diastole (D wave), velocity between S and D waves (S-D velocity) and during atrial contraction (a wave) and of the angle-independent indexes. Methods: This is a prospective transversal study on 276 single gestations. Multiple gestations, fetal malformation, fetuses with increased nuchal translucency (NT) and pregnant women with clinical pathologies were excluded of this study. The equipment used was Toshiba-model SSH-140 A. Levene's test was used to calculate variance homogeneity among the variables. The statistical study was performed by means of the variance analysis with multiple comparisons by the Bonferroni's method. Results: S and D velocities presented a slightly increased pattern in relation to the studied gestational ages (descriptive level varying from 0.001 and 0.029), a wave, S-D velocity and all angle-independent indexes presented a constant pattern in the studied period. Conclusion: The lack of important modifications in the ductus venosus flow velocity waveform is due to the fact that reduction in placental resistance and maturation in the ventricular diastolic function only occurs after this period. The values established by this study may be of help in the follow-up of normal gestations, diagnosis of fetal myocardial failure or screening for chromosomal disorders. Objective: To test the usefulness of Doppler indices in lung vessels to discriminate between normal and stimulated fetal lung growth. Methods: In singleton sheep fetuses (gestational age 92-98 days) the trachea was ligated immediately caudal of the larynx (TO, n = 6). Blood flow velocities Vpeak, Vmin, TAMX and the pulsatility (PI) and resistance indices (RI) were determined (Acuson Aspen) in both pulmonary arteries (PAL: left; PAR: right), the pulmonary trunk (PT) and ductus arteriosus (DA) of these TO fetuses and in three controls (CTRL). These measurements were repeated weekly under slight sedation (xylaz...