Sonographic measurement of the umbilical cord and fetal anthropometric parameters

Objective: To determine reference ranges for the diameter and the cross-sectional area of the umbilical cord during pregnancy and to determine if umbilical cord morphometry is related to fetal size. Methods: A prospective cross-sectional study was designed to assess the sonographic cross-sectional diameter and area of the umbilical cord. The sonographic umbilical cord measurements were obtained in a plane adjacent to the insertion of the cord into the fetal abdomen. Nomograms for the umbilical cord diameter and area were computed. Fetal biometry included: biparietal diameter, abdominal circumference, and femur length. Polynomial regression analysis was conducted. Results: Five hundred and fifty seven patients were included into the study. The regression equation for the umbilical cord diameter (y) according to gestational age (x) was y=-10.0563+1.4265x+0.0194x2 and for the umbilical cord area (y') was y'=91.6-3.3x+0.03x2-0.00007x3. A significant relationship was found between umbilical cord measurements and fetal anthropometric parameters. Conclusion: Reference ranges for umbilical cord diameter and area have been generated. The sonographic diameter and cross-sectional area of the umbilical cord increase as a function of gestational age and both diameter and area correlate with fetal size. Copyright (C) 1999 Elsevier Science Ireland Ltd

A new approach to fetal echocardiography: digital casts of the fetal cardiac chambers and great vessels for detection of congenital heart disease

OBJECTIVE: The purpose of this study was to describe a method of 4-dimensional (4D) reconstruction of the cardiac chambers and outflow tracts using a combination of spatiotemporal image correlation, "inversion mode," and "B-flow" imaging. METHODS: Spatiotemporal image correlation and the inversion mode were used in the examination of the volume data sets of 23 fetuses with congenital heart anomalies. A subset was also examined with B-flow imaging using the gradient light algorithm. Digital reconstructions from abnormal hearts were compared with a library obtained from fetuses without abnormalities. RESULTS: Rendered images of the 4-chamber view using the inversion mode were characterized by: (1) echogenic chambers; (2) sharp delineation of chamber contours when compared with 2-dimensional (2D) images; and (3) distinct display of the myocardium, interventricular septum, interatrial septum, and mitral and tricuspid valves as anechoic structures. Ventricular septal defects, abnormal differential insertion of the atrioventricular valves, and valve atresia were well visualized with the inversion mode. The application of inversion mode or B-flow imaging to 4D rendering of the outflow tracts resulted in "digital casts" displaying the spatial relationships between the outflow tracts as well as the connections between the great arteries and ventricular chambers. The spatial relationships and communications among cardiac structures cannot be visualized with conventional 2D ultrasonography. CONCLUSIONS: The application of spatiotemporal image correlation, inversion mode, and B-flow imaging generates information about the anatomy and pathologic characteristics of the fetal heart (digital casts) that cannot be obtained with 2D fetal echocardiography. We propose that these modalities enhance the information provided by ultrasonographic interrogation of the fetal heart and will improve prenatal diagnosis

Placental vascular pathology and increased thrombin generation as mechanisms of disease in obstetrical syndromes

Obstetrical complications including preeclampsia, fetal growth restriction, preterm labor, preterm prelabor rupture of membranes and fetal demise are all the clinical endpoint of several underlying mechanisms (i.e., infection, inflammation, thrombosis, endocrine disorder, immunologic rejection, genetic, and environmental), therefore, they may be regarded as syndromes. Placental vascular pathology and increased thrombin generation were reported in all of these obstetrical syndromes. Moreover, elevated concentrations of thrombin-anti thrombin III complexes and changes in the coagulation as well as anticoagulation factors can be detected in the maternal circulation prior to the clinical development of the disease in some of these syndromes. In this review, we will assess the changes in the hemostatic system during normal and complicated pregnancy in maternal blood, maternal–fetal interface and amniotic fluid, and describe the contribution of thrombosis and vascular pathology to the development of the great obstetrical syndromes

Amniotic fluid 5-hydroxyeicosatetraenoic acid in preterm labor

5-Hydroxyeicosatetraenoic acid (5-HETE) is an arachidonate lipoxygenase product capable of stimulating human uterine contractility in a dose-dependent manner in vitro. The purpose of this study was to determine if preterm labor is associated with changes in the concentration of this metabolite in amniotic fluid. Amniotic fluid was obtained by transabdominal amniocentesis from three groups of women with preterm labor: group 1 - women without intraamniotic infection who responded to tocolysis (n = 32); group 2 - women without intraamniotic infection who failed to respond to tocolysis (n = 22); and group 3 - women with intraamniotic infection (n = 14). 5-HETE was determined by radioimmunoassay. The median amniotic fluid concentration of 5-HETE in women who responded to tocolysis (median = 1412 pg/ml; range: 111-3547) was significantly lower than in women who delivered despite tocolysis (median = 2052 pg/ml; range: 136-7774) and women with intraamniotic infection (median = 1876 pg/ml; range: 543-7033) [p 0.05)