The precision and accuracy of symphysis--fundus distance measurements during pregnancy.
We studied the precision and accuracy of SF measurements. Five trained obstetricians made three measurements of SF on each of 33 patients in the third trimester. The intraobserver variation varied from 0 cm to 8 cm, and comprised on average 1.5 to 2 cm (95th centiles 2.5 to 4 cm). The interobserver variation varied from 1 to 13 cm, and comprised on average 4 cm (95th centile 8 cm). The accuracy of SF measurements was estimated by comparison with ultrasound-guided measurements, which showed a very high precision. Two of the investigators differed significantly, by -1.56 cm and -1.97 cm, from the other 3.
D002983:Clinical Competence; D005314:Embryonic and Fetal Development; D005260:Female; D006801:Humans; D011247:Pregnancy; D011263:Pregnancy Trimester, Third; D011631:Pubic Symphysis / Q000033:anatomy & histology*; D014463:Ultrasonography; D014599:Uterus / Q000033:anatomy & histology*