Wesley Lee

Nasal Bone Evaluation in Fetuses With Down Syndrome During the Second and Third Trimesters of Pregnancy

Objective. This study examined the use of three‐dimensional ultrasonography for evaluating the fetal nasal bone, as a sonographic marker of Down syndrome, during the second and early third trimesters of pregnancy. Methods. Forty fetuses, including 20 with trisomy 21, were scanned once by three‐dimensional ultrasonography. A midline sagittal view of the facial profile was used to analyze the volume data. Independent examiners reviewed blinded and randomly allocated volume data sets for the nasal bone. Interobserver reliability was evaluated for the sonographic presence or absence of the nasal bone. Logistic regression determined the contribution of this parameter to the presence of Down syndrome. Results. Both examiners showed substantial agreement in scoring whether the nasal bone was visualized by three‐dimensional ultrasonography (P < .001). They identified 40% to 45% of fetuses with abnormalities using the absence of the nasal bone as a sonographic marker. However, a substantial number of fetuses with abnormalities were also found to have a nasal bone present. The nasal bone was visualized in 80% to 90% of fetuses without abnormalities. Conclusions. Three‐dimensional ultrasonography can be used to evaluate the fetal nasal bone with substantial interobserver agreement during the second and early third trimesters of pregnancy. A nonvisualized nasal bone identified 40% to 45% of fetuses with Down syndrome in this study.

Maternal diabetes mellitus: Which views are essential for fetal echocardiography?

Objective To determine which fetal echocardiography views are essential to detect the majority of cardiac defects in fetuses of women with diabetes mellitus. Methods Fetal echocardiograms performed from February 1990 through May 1996 on insulin-requiring women with diabetes were reviewed. Individual component views of the examination were analyzed for the detection of fetal congenital heart defects. Sensitivity, specificity, positive predictive value, and negative predictive value were calculated. Multiple gestations and patients with additional risk factors for congenital heart defects were excluded. Results A total of 223 patients were included in the study. There were 11 (4.9%) congenital heart defects, eight of which were conotruncal. When the four-chamber view and outflow tracts appeared normal, additional views such as the ductal and aortic arches did not detect a cardiac defect. The sensitivity of the four-chamber view for detecting an abnormal heart increased from 73% to 82% with the addition of the aortic outflow tract. There were two false-negative and no false-positive diagnoses. Conclusion the four-chamber and outflow tracts are the essential views that will detect most cardiac defects in fetuses of women with insulin-requiring diabetes mellitus.

4D Fetal Echocardiography

Congenital heart defects (CHD) are the most frequent malformation in the human fetus and are the leading cause of mortality due to malformations in the first year of life. Despite its clinical importance screening performed by ultrasonographic examination during the second trimester of pregnancy has shown disappointingly low detection rates mainly due to the difficulties in obtaining an adequate examination of the fetal heart. Four-dimensional (4D) ultrasound of the fetal heart has been recently suggested as a tool to improve the detection rate of CHD by decreasing the dependency on operator skills required in two-dimensional ultrasound scans but up to now no practical manuals are available in describing its application in clinical practice for the study of fetal heart. The objective of this Ebook is to explain the role of 4D during second trimester examination and in fetuses with CHD. The technique of obtaining 4D volume of the fetal heart, how to navigate in the volume to obtain diagnostic planes and how to use semiautomatic and automatic software of analysis are described. We believe that after reading this book the standard fetal cardiac anatomy survey can be performed in the second trimester fetus by 4D in both normal and abnormal hearts. This approach may reduce the operator dependency in diagnosis CHD. This Ebook should prove to be a valuable resource for obstetricians, sonographers and pediatric cardiologists.