The Experts below are selected from a list of 9279 Experts worldwide ranked by ideXlab platform
S Farzanfar - One of the best experts on this subject based on the ideXlab platform.
-
Relationship of small-for-dates sac size to Crown-Rump Length and spontaneous abortion in patients with a known date of ovulation.
Obstetrics and gynecology, 1991Co-Authors: A Nazari, R H Epstein, Carole Dietterich, Jerome H. Check, S FarzanfarAbstract:Spontaneous abortion after established sonographic viability is rare. This study prospectively evaluated 39 late first-trimester abortions after fetal viability was established by ultrasound. The average Crown-Rump Length measurement and mean sac diameter in this group were determined and compared with predicted values based on known conception dates, and the discrepancy between actual and predicted measurements was noted. The same calculations were then made on 39 prospectively matched non-aborting controls. We also determined the difference between sac size and Crown-Rump Length in both groups. Significant differences were found for all three measures. Small-for-dates sac size and small-for-dates Crown-Rump Length were defined as having a discrepancy score greater than 1 standard deviation (SD) above normal. Small-for-dates sac/Crown-Rump Length was defined as having a discrepancy score less than 1 SD below normal. A high percentage of aborters was correctly predicted by a mean sac diameter (82%) or Crown-Rump Length (77%) that was greater than +1 SD, with few false positives (12.8 and 5.1%, respectively). The cutoff for differences of sac minus Crown-Rump Length measurements (10.1 mm) was less sensitive (56%), but just as specific (82%). When both the mean sac diameter and Crown-Rump Length were smaller than expected (according to known date of ovulation), the ability to predict abortion was 71% with few false positives (3.5%).
Salim Daya - One of the best experts on this subject based on the ideXlab platform.
-
Accuracy of gestational age estimation by means of fetal Crown-Rump Length measurement.
American Journal of Obstetrics and Gynecology, 1993Co-Authors: Salim DayaAbstract:OBJECTIVE: The purpose of this study was to develop a gestational age table by means of Crown-Rump Length measurements in the first trimester in pregnancies conceived through in vitro fertilization. STUDY DESIGN: Ninety-four infertile women with singleton intrauterine pregnancies resulting from in vitro fertilization underwent ultrasonographic examinations in the first trimester. The relationship between gestational age (calculated with the day of oocyte retrieval used as day 14) and the Crown-Rump Length was explored with regression analysis. RESULTS: A quadratic model demonstrated the best fit to the data, indicating a curvilinear relationship between Crown-Rump Length and gestational age. Estimates of gestational age with Crown-Rump Length measurements between 40 and 60 mm were observed to be similar to published tables, but outside this range the tables either overestimate or underestimate the true gestational age. CONCLUSION: A more accurate equation for gestational age estimation with Crown-Rump Length measurements in early pregnancy has been developed with in vitro fertilization pregnancy data.
-
Accuracy of gestational age estimation by means of fetal Crown-Rump Length measurement.
American journal of obstetrics and gynecology, 1993Co-Authors: Salim DayaAbstract:The purpose of this study was to develop a gestational age table by means of Crown-Rump Length measurements in the first trimester in pregnancies conceived through in vitro fertilization. Ninety-four infertile women with singleton intrauterine pregnancies resulting from in vitro fertilization underwent ultrasonographic examinations in the first trimester. The relationship between gestational age (calculated with the day of oocyte retrieval used as day 14) and the Crown-Rump Length was explored with regression analysis. A quadratic model demonstrated the best fit to the data, indicating a curvilinear relationship between Crown-Rump Length and gestational age. Estimates of gestational age with Crown-Rump Length measurements between 40 and 60 mm were observed to be similar to published tables, but outside this range the tables either overestimate or underestimate the true gestational age. A more accurate equation for gestational age estimation with Crown-Rump Length measurements in early pregnancy has been developed with in vitro fertilization pregnancy data.
Aris T. Papageorghiou - One of the best experts on this subject based on the ideXlab platform.
-
Image-scoring system for Crown-Rump Length measurement.
Ultrasound in obstetrics & gynecology : the official journal of the International Society of Ultrasound in Obstetrics and Gynecology, 2014Co-Authors: Sikolia Wanyonyi, Laurent Salomon, Raffaele Napolitano, Eric O Ohuma, Aris T. PapageorghiouAbstract:Objective To develop and evaluate an objective image-scoring system for Crown–Rump Length (CRL) measurements and to determine how this compares with subjective assessment. Methods A total of 125 CRL ultrasound images were selected from the database of the International Fetal and Newborn Growth Consortium for the 21st Century study group. Two reviewers, who were blinded to the operators' and to each others' results, evaluated all images both subjectively and objectively. Subjective evaluation consisted of rating an image as acceptable or unacceptable, while objective evaluation was based on six criteria. Reviewer differences for both the subjective and objective evaluations were compared using percentage of agreement and adjusted kappa values. Results The distribution of individual scores and differences between subjective and objective evaluation for the two reviewers was similar. Overall agreement between the reviewers was higher for objective evaluation (95.2%; adjusted κ, 0.904), than for subjective evaluation (77.6%; adjusted κ, 0.552). There was a high level of agreement for horizontal position (κ = 0.951), magnification (κ = 0.919), visualization of Crown and Rump (κ = 0.806) and caliper placement (κ = 0.756), while agreement for mid-sagittal section (κ = 0.629) and neutral position (κ = 0.565) were moderate and poor, respectively. Conclusion The proposed six-point scoring system for CRL image rating is more reproducible than is subjective evaluation and should be considered as a method of quality assessment and audit. Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd.
-
Standardisation of Crown–Rump Length measurement
British Journal of Obstetrics and Gynaecology, 2013Co-Authors: Charalampos Ioannou, Ioannis Sarris, L Hoch, Laurent Salomon, Aris T. PapageorghiouAbstract:Correct estimation of gestational age is essential for any study of ultrasound biometry and for everyday clinical practice. However, inconsistency in pregnancy dating may occur through differences in measurement methods or errors during measurement. In the INTERGROWTH-21(st) Project, pregnancies are dated by the last menstrual period, provided that it is certain and associated with a regular menstrual cycle, and the gestational age by dates concurs with a first-trimester ultrasound Crown-Rump Length (CRL) estimation. Hence, there was a need to standardise CRL measurement methodology across the study sites in this international, multicentre project to avoid systematic differences in dating. To achieve uniformity we undertook the following steps: the ultrasound technique was standardised by disseminating an illustrated, operating manual describing CRL plane landmarks and calliper application, and posters describing the correct acquisition technique were disseminated for quick reference. To ensure that all ultrasonographers understood the methodology, they forwarded a log-book to the INTERGROWTH-21(st) Ultrasound Coordinating Unit, containing the answers to a written test on the manual material and five images of a correctly acquired CRL. Interpretation of CRL was also standardised by ensuring that the same CRL regression formula was used across all study sites. These methods should minimise potential systematic errors in dating associated with pooling data from different health institutions, and represent a model for standardising CRL measurement in future studies.
-
Standardisation of Crown-Rump Length measurement.
BJOG : an international journal of obstetrics and gynaecology, 2013Co-Authors: Charalampos Ioannou, L. J. Salomon, Ioannis Sarris, L Hoch, Aris T. PapageorghiouAbstract:Correct estimation of gestational age is essential for any study of ultrasound biometry and for everyday clinical practice. However, inconsistency in pregnancy dating may occur through differences in measurement methods or errors during measurement. In the INTERGROWTH-21(st) Project, pregnancies are dated by the last menstrual period, provided that it is certain and associated with a regular menstrual cycle, and the gestational age by dates concurs with a first-trimester ultrasound Crown-Rump Length (CRL) estimation. Hence, there was a need to standardise CRL measurement methodology across the study sites in this international, multicentre project to avoid systematic differences in dating. To achieve uniformity we undertook the following steps: the ultrasound technique was standardised by disseminating an illustrated, operating manual describing CRL plane landmarks and calliper application, and posters describing the correct acquisition technique were disseminated for quick reference. To ensure that all ultrasonographers understood the methodology, they forwarded a log-book to the INTERGROWTH-21(st) Ultrasound Coordinating Unit, containing the answers to a written test on the manual material and five images of a correctly acquired CRL. Interpretation of CRL was also standardised by ensuring that the same CRL regression formula was used across all study sites. These methods should minimise potential systematic errors in dating associated with pooling data from different health institutions, and represent a model for standardising CRL measurement in future studies.
William A Grobman - One of the best experts on this subject based on the ideXlab platform.
-
The association of Crown-Rump Length discordance in twin gestations with adverse perinatal outcomes
American Journal of Obstetrics and Gynecology, 2007Co-Authors: William A GrobmanAbstract:Objective The purpose of this study was to evaluate the association between the Crown-Rump Length (CRL) difference in twin gestations and adverse pregnancy outcome. Study Design Women with a first trimester ultrasound scan of a twin pregnancy who delivered between June 2000 and March 2006 at Northwestern Memorial Hospital were identified. The association between the difference in CRLs and pregnancy outcomes was explored. Results For the 178 twins who were eligible for the study, the median difference in CRLs was 4.2% and the median difference in birthweights was 9.3%. Twins with a CRL difference of >85th percentile (11.1%) were more likely to have discordant birthweights and to have at least 1 of the pair be small-for-gestational age, be admitted to the special care nursery, and have perinatal morbidity. Conclusion CRL differences of >85th percentile are associated with several measures of adverse perinatal outcome.
-
The association of Crown-Rump Length discordance in twin gestations with adverse perinatal outcomes.
American journal of obstetrics and gynecology, 2007Co-Authors: Judy Tai, William A GrobmanAbstract:The purpose of this study was to evaluate the association between the Crown-Rump Length (CRL) difference in twin gestations and adverse pregnancy outcome. Women with a first trimester ultrasound scan of a twin pregnancy who delivered between June 2000 and March 2006 at Northwestern Memorial Hospital were identified. The association between the difference in CRLs and pregnancy outcomes was explored. For the 178 twins who were eligible for the study, the median difference in CRLs was 4.2% and the median difference in birthweights was 9.3%. Twins with a CRL difference of >85th percentile (11.1%) were more likely to have discordant birthweights and to have at least 1 of the pair be small-for-gestational age, be admitted to the special care nursery, and have perinatal morbidity. CRL differences of >85th percentile are associated with several measures of adverse perinatal outcome.
A Nazari - One of the best experts on this subject based on the ideXlab platform.
-
Relationship of small-for-dates sac size to Crown-Rump Length and spontaneous abortion in patients with a known date of ovulation.
Obstetrics and gynecology, 1991Co-Authors: A Nazari, R H Epstein, Carole Dietterich, Jerome H. Check, S FarzanfarAbstract:Spontaneous abortion after established sonographic viability is rare. This study prospectively evaluated 39 late first-trimester abortions after fetal viability was established by ultrasound. The average Crown-Rump Length measurement and mean sac diameter in this group were determined and compared with predicted values based on known conception dates, and the discrepancy between actual and predicted measurements was noted. The same calculations were then made on 39 prospectively matched non-aborting controls. We also determined the difference between sac size and Crown-Rump Length in both groups. Significant differences were found for all three measures. Small-for-dates sac size and small-for-dates Crown-Rump Length were defined as having a discrepancy score greater than 1 standard deviation (SD) above normal. Small-for-dates sac/Crown-Rump Length was defined as having a discrepancy score less than 1 SD below normal. A high percentage of aborters was correctly predicted by a mean sac diameter (82%) or Crown-Rump Length (77%) that was greater than +1 SD, with few false positives (12.8 and 5.1%, respectively). The cutoff for differences of sac minus Crown-Rump Length measurements (10.1 mm) was less sensitive (56%), but just as specific (82%). When both the mean sac diameter and Crown-Rump Length were smaller than expected (according to known date of ovulation), the ability to predict abortion was 71% with few false positives (3.5%).