Fetal Measurements And Growth Flashcards
Used in first trimester to estimate GA when no embryo is visualized
Gestational sac size
Crown-rump length is taken from top of head to
Bottom of torso
CRL is useful until what GA
12 weeks
Biparietal diameter is measured on an axial image of the fetal head at the level of _____ to ______
3rd ventricle and thalamus
Outer table of near cranium to inner table of far cranium
Elongated skill
Dolicocephaly
Round skull
Brachycephaly
Outer perimeter of fetal cranium measured in the same plane as the BPD
Head circumference
Independent of head shape
Head circumference
Abdominal circumference is measured on an axial plane image at the level of
Intrahepatic portion of umbilical vein
Measurement of the ossified portion of femoral diaphysis
Femur length
Composite of BPD, HC, AC and FL measurements predicrs GA accurate to about 1.1 weeks at
12-18 weeks
Composite of BPD, HC, AC and FL measurements predicrs GA accurate to about 1.8 weeks at
24-30 weeks
Composite of BPD, HC, AC and FL measurements predicrs GA accurate to about 3.1 weeks at
36-42 weeks
Used to measure BPD and HC
Transthalamic plane
Axial plane at the level of the ventricular atria. Dominant landmark is the echogenic choroid plexus
Transventricular plane
Axial scan approximately 10-15 degrees of inclination from the canthomeatal line. Anatomic landmarks include the inferior portion of the third ventricle and cerebellar hemispheres outlined by fluid in cisterna magna
Transcerebellar plane
Normal cisterna magna is ____ in width
2-11 mm
Ventricle atria width
Less than 10mm
What part of liver is larger in the fetus, right or left?
Left lobe
Half the blood it carries goes directly to IVC through the ductus venosus and the other half perfuses the liver thru the left portal vein
Umbilical vein
20 times larger in relative size because of presence of “fetal zone”
Adrenal glands
Fetal stomach should be filled with swallowed fluid by what weeks
18 weeks
Small bowl peristalsis may be seen by
3rd trimester
Small bowel loop normal diameter and length in fetus
6 mm diameter, 15 mm length
Colon is visualized after ____ weeks as a tubular structure around the periphery of abdomen
20 weeks
Normal colon diameter of fetus
23 mm
Length of normal fetal kidneys in mm is approximately equal to
GA in weeks
