Chapter 18 Flashcards
What is macrosomia?
Fetus over 4000 g (8lbs 13 ounces)
What is cephalon index?
The ratio of the BPD to the OFD
What is occipitofrontal diameter?
Measurement from the frontal to the occipital obtained at the same level as the BPD
What is predictive value?
Precision rate of the probability of disease
The fetal expected birthdate is known as the EDC or the?
EDD
The most accurate fetal measurement can be obtained from:
Multiple parameters
Which phase of pregnancy provides the most accurate dating?
Early embryo measurements
The preferred measurement method for fetal growth is:
The average of multiple measurements within a “cluster”
The normal duration of pregnancy is:
40 weeks from the LMP (38 week gestation +/- 2 to 3 weeks)
The most accurate fetal measurements are taken:
Along the beam axis using axial resolution
Ultrasound measurement errors due to beam width and machine calibration of __________ are acceptable.
1 or 2mm/10cm
The most common and routine measurements to assess the fetal growth and well being are:
BPD, HC, AC and FL
What structures are seen in an accurate BPD measurement?
complete oval calvarium slightly superior to the parietal, sphenoid, petrous ridge structures
To estimate an accurate fetal age, the BPD measurement should be obtained before:
33 weeks
An HC measurement should be obtained:
using the outer edge of the calvarium at the level of the BPD
