The use of ultrasonic fetal head circumference for predicting expected date of confinement.
An ultrasonic fetal head circumference curve was developed from a group of 1278 ultrasound examinations in 710 normal obstetrical patients. These data were then used to compare the accuracy of head circumference (HC) to last menstrual period (LMP) and biparietal diameter (BPD) for the prediction of an accurate expected date of confinement (EDC) and, thereby calculate gestational age. The mean error of the signed differences (+/- standard deviation) for HC was -0.8 +/- 11.1 days, which was statistically different from the mean error of -6.1 +/- 10.6 days for BPD and -2.8 +/- 17.8 days for LMP. HC may have an advantage over BPD in situations where head shape (cephalic index) is significantly altered.
D005260:Female; D005865:Gestational Age; D006801:Humans; D011247:Pregnancy; D012015:Reference Standards; D012886:Skull / Q000033:anatomy & histology / Q000196:embryology*; D014463:Ultrasonography