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An evaluation of two methods for measuring fetal head and body circumferences.
Author(s) -
Hadlock F P,
Kent W R,
Loyd J L,
Harrist R B,
Deter R L,
Park S K
Publication year - 1982
Publication title -
journal of ultrasound in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 91
eISSN - 1550-9613
pISSN - 0278-4297
DOI - 10.7863/jum.1982.1.9.359
Subject(s) - medicine , circumference , fetal head , head circumference , ellipse , statistics , nuclear medicine , fetus , orthodontics , pregnancy , mathematics , geometry , birth weight , biology , genetics
Head and abdominal circumference measurements of 166 fetuses (15‐40 weeks) were made by three different examiners using two measurement techniques. In method 1 the actual circumferences were measured using an electronic digitizer, while in method 2 the circumference measurements were estimated using the formula for calculating the circumference for an ellipse. Evaluation of the entire data set as a whole demonstrated no significant mean errors (P > 0.05), and only a small degree of variability (2 SD = 6 per cent). Evaluation of the data for each examiner demonstrated no significant differences (P > 0.05) in the observed variability, but small statistically significant mean errors (1.7‐4.1 per cent) were observed. The latter finding is thought not to be a limitation of the ellipse approximation technique, since similar findings have been observed when experienced sonographers make actual circumference measurements on the same fetus using the same equipment.