Fetal Biometry

Question 1

What is the most accurate sonographic method for determining gestational age?

Answer 1

CRL

pg. E 174

Question 2

If the AC falls below 2 SD, what can it indicate?

Answer 2

IUGR

pg. E 174

Question 3

If the FL falls below 2 SD, what can it indicate?

Answer 3

skeletal dysplasia

pg. E 174

Question 4

If the head and/or AC fall short, what should be calculated?

Answer 4

HC/AC ratio

pg. E 174

Question 5

What does Nagele’s Rule determine?

Answer 5

due date from LMP

pg. E 174

Question 6

What is Nagele’s Rule equation?

Answer 6

EDC = LMP - 3 months + 7 days

pg. E 174

Question 7

What is a cephalic index?

Answer 7

defines head shape by dividing BPD by OFD

pg. E 174

Question 8

What is the normal range for a cephalic index?

Answer 8

0. 70 - 0.86

pg. E 174

Question 9

When is a head considered dolichocephaly?

Answer 9

CI < 0.70

pg. E 174

Question 10

When is a head considered brachycephaly?

Answer 10

CI > 0.86

pg. E 174

Question 11

How is OFD measured?

Answer 11

outer to outer (anterior to posterior skull)

pg. E 175

Question 12

At what level is the AC taken?

Answer 12

stomach
portal sinus of umbilical vein
pg. E 175

Question 13

What is included in the circumference of the abdomen?

Answer 13

along skin line to include soft tissue and fat

pg. E 175

Question 14

What is included in the circumference of the head?

Answer 14

not include scalp

pg. E 175

Question 15

Which measurement is the least reliable in establishing gestational age?

Answer 15

AC

pg. E 174

Question 16

When is the distal femoral epiphysis visualized?

Answer 16

33 weeks

pg. E 176

Question 17

What is binocular distance?

Answer 17

measurement from lateral orbital rim to lateral orbital rim

pg. E 176

Question 18

What is included in a BPP?

Answer 18

fetal breathing
gross body movements
fetal tone
amniotic fluid
NST
pg. E 177

Question 19

What is footling breech?

Answer 19

hips extended
feet presenting
pg. E 178

Question 20

What is frank breech?

Answer 20

hips flexed
knee extended
pg. E 178

Question 21

What is complete breech?

Answer 21

hips flexed
knees flexed
pg. E 178

Question 22

A BPD greater than __ cm can indicate macrosomia.

Answer 22

10

Question 23

What fluid measurement is taken with twins?

Answer 23

maximum vertical pocket

Question 24

What is included in the NST?

Answer 24

Doppler records fetal heart rate

Stress is added and baby’s heart rate should accelerate

Question 25

Cerebellum is equal to gestational age up to how many weeks?

Answer 25

28 weeks

Question 26

When does CRL become invalid for fetal dating?

Answer 26

12 weeks