OP11.03: Intra‐ and inter‐observer variability of crown–rump length and other fetal biometry at the nuchal translucency scan
Year: 2011
Type: conference-abstract
Abstract: In the first trimester screening process for fetuses between 11 + 0 to 13 + 6 weeks, crown–rump length has been utilized as the gold standard for dating pregnancies and interpreting screening results. Other fetal biometric measurements have sometimes been employed to confirm gestational age, but not to interpret the results. The purpose of this study is the compare the intra-observer and inter-observer variability of crown–rump length and other fetal biometric measurements in the first trimester. The goal is to determine which measurement has the least variability when repeated by the same and two different examiners. Women presenting to an academic fetal diagnostic center between 11 + 0 and 13 + 6 weeks of pregnancy for a nuchal translucency scan were examined by one sonographer followed by one physician. Each examiner obtained 3 independent measurements of crown rump length, bi-parietal diameter, head circumference, abdominal circumference, femur and humeral lengths, and nuchal translucency. Patients were excluded for fetal malformations or demise. Coefficients of variance were calculated for each biometric measure both within an exam and between examiners in the within exam means. The biometric measure with the smallest coefficient of variance was regarded as the most precise for determining the gestational age for screening. Measurements were obtained on 135 fetuses. Crown–rump length had the smallest within exam coefficient of variance, 1.2%, with the others biometric measures ranging from 1.4 to 6.6%; both this measure and bi-parietal diameter had the smallest between-examiner value of 1.9% compared with 2.0–6.9%. By comparison, the imprecision of nuchal translucency measurement was greater, with values of 4.9% (within exam) and 6.5% (between-examiner) respectively. Crown–rump length is the most precise biometric measurement at the nuchal translucency scan. Nuchal translucency is measured with less precision than CRL.
DOI: 10.1002/uog.9362
Language: English
Field: Medicine
Domain: Health Sciences
Open Access status: bronze
OpenAlex ID: W1540317046