. Author manuscript; available in PMC: 2012 Sep 11.

Published in final edited form as: Ultrasound Obstet Gynecol. 2009 Oct;34(4):395–403. doi: 10.1002/uog.7350

Table 3.

Mean difference and 95% limits of agreement (LOA) by measurement and corresponding estimated gestational age of ultrasound measurements obtained by two different examiners on 90 fetuses at 18–24 weeks’ gestation

Parameter	n	Measurement			Gestational age
Parameter	n	Mean difference (mm (95% CI))	SD (mm)	95% LOA (mm)	Mean difference (weeks (95% CI))	SD (weeks)
BPD	90	−0.43 (−0.68 to −0.17)	1.21	−2.80 to 1.94	−0.12 (−0.19 to −0.04)	0.36
HC	90	−1.63 (−2.63 to −0.62)	4.80	−11.0 to 7.77	−0.12 (−0.20 to −0.03)	0.42
AC	90	−0.59 (−1.77 to 0.60)	5.65	−11.7 to 10.45	−0.03 (−0.13 to 0.07)	0.50
FL	90	−0.35 (−0.64 to −0.07)	1.37	−3.03 to 2.33	−0.11 (−0.21 to 0)	0.50

AC, abdominal circumference; BPD, biparietal diameter; FL, femur length; HC, head circumference.