We have located links that may give you full text access.
Endovaginal ultrasonographic measurement of early embryonic size as a means of assessing gestational age.
Journal of Ultrasound in Medicine : Official Journal of the American Institute of Ultrasound in Medicine 1994 January
Crown-rump length has consistently been found to be the most accurate method of determining gestational age in the first trimester. The original regression curve established by Robinson in 1973 with static arm scanners remains the one most widely employed. New endovaginal ultrasonographic probes afford a degree of detail that allows embryonic structures to be seen as soon as they are distinct from the yolk sac. Previously, measurements of very early embryonic structures have mistakenly been labeled crown-rump lengths. There has been widespread use of nomograms constructed from regression curves, where the bulk of the data were derived from small fetuses and then such curves extrapolated back to embryos of very small size. The purpose of this study was to establish a nomogram for gestational age assessment by measuring early embryos prior to the development of a "crown" or "rump." This present study consisted of 143 patients. To be included they had to have had no history of any prior bleeding, and all were delivered of singleton infants within 2 weeks of their estimated delivery date by last menstrual period. All had a single early embryonic size measurement between 1 and 25 mm using high-frequency endovaginal probes. Regression analysis revealed a linear equation of Gestational age (days) = early embryonic size (mm) + 42 with a correlation coefficient r = 0.87; 95% confidence limit = +/- 3 days. We conclude that using high-frequency vaginal ultrasonographic probes and having a better understanding of embryonic anatomic stages allow for the construction of a nomogram of gestational age derived from measurements of early embryonic size prior to development of a crown-rump length.
Full text links
Related Resources
Trending Papers
Heart failure with preserved ejection fraction: diagnosis, risk assessment, and treatment.Clinical Research in Cardiology : Official Journal of the German Cardiac Society 2024 April 12
Proximal versus distal diuretics in congestive heart failure.Nephrology, Dialysis, Transplantation 2024 Februrary 30
Efficacy and safety of pharmacotherapy in chronic insomnia: A review of clinical guidelines and case reports.Mental Health Clinician 2023 October
World Health Organization and International Consensus Classification of eosinophilic disorders: 2024 update on diagnosis, risk stratification, and management.American Journal of Hematology 2024 March 30
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app
All material on this website is protected by copyright, Copyright © 1994-2024 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.
By using this service, you agree to our terms of use and privacy policy.
Your Privacy Choices
You can now claim free CME credits for this literature searchClaim now
Get seemless 1-tap access through your institution/university
For the best experience, use the Read mobile app