Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MIDS 187 > Ch 1b Biometry > Flashcards

Ch 1b Biometry Flashcards

1
Q

What 4 reasons are why we do fetal biometry?

A

-To plan the mode/way the baby will be delivered along with the date of delivery
-To screen for aneuploidy (chromosome abnormalities)
-Determining dates for termination
-Fetal growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

EDD vs EDC meaning?

A

-Estimated date of delivery
-Estimated date of confinement

(both mean same thing)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

An important estimator of fetal health is what?

A

Fetal size

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What 4 factors affect fetal biometry?

A

-Ethnic diversity
-Altitude
-Genetics
-Smoking

(remember these are NOT taken into consideration when dating or assessing growth)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

When assessing growth, do we take an average of our measurements or take the largest?

A

Growth: average
Dating: largest

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How can we improve our accuracy when assessing growth?

A

Average multiple measurements (typically 2-3 measurements done)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Measurements should cluster within how many mm of each other?

A

Within 2-3mm (outliers are discarded/deleted)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What 3 fetal factors can affect measurements?

A

-PROM (premature rupture of membranes)
-Hydrocephalus
-Maternal diabetes

(can be mitigated/less severe by obtaining at least a BPD, HC, AC + FL)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Why does PROM affect measurements?

A

B/c it can cause uterine pressure on the fetal head affecting the BPD

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Why do we use multiple parameters when scanning a baby?

A

B/c it minimizes errors + fetal variations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Landmarks for HC?

A

Thalamus in center, cavum septum pellucidi anteriorly + interhemispheric fissure at midline

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How do we measure the BPD?

A

Outer parietal bone to inner parietal bone

(parietal bones form the lateral walls of skull)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What if we measure the BPD with the fetal face facing anterior or posterior?

A

May be inaccurate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is dolicocephaly + brachycephaly?

A

Dolicocephaly: long + narrow head
Brachycephaly: short + wide head

(these affect our BPD)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Is a BPD or HC more accurate?

A

HC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

How should a proper HC be done?

A

Measurement should hug the outer bony skull as tightly as possible + avoid including the skin!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Formula for cephalic index?

A

BPD/FOD x 100

(FOD = frontal occipital distance)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How is FOD measured?

A

Outer to outer

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the normal cephalic index?

A

Less than 80%

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What is the BPD + cephalic index like with a dolichocephalic head?

A

BPD: short
CI: below normal

(long FOD)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What is the BPD, cephalic index + frontal occipital distance like with a brachycephalic head?

A

BPD: wide
CI: above normal
FOD: short

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Landmarks for TRV cerebellum measurement?

A

CSP, thalamus, falx cerebri + cerebellar hemispheres

23
Q

Purpose of the TRV cerebellar diameter?

A

Assess growth

24
Q

Is the TRV cerebellar diameter dependent or independent of the fetal head shape?

A

Independent

25
Q

What does the binocular distance (BOD) measure?

A

-Distance from outer edge of right + left fetal eyes

(outer orbit to outer orbit (OOD) distance from edges of skeletal orbit)

26
Q

Is a binocular distance routinely done?

A

No, often do BOD when looking for hypertelorism (eyes far apart) and hypotelorism (eyes close together)

27
Q

Abdominal circumference landmarks?

A

Stomach, umbilical vein + portal vein

28
Q

Why do we do an abdominal circumference?

A

B/c it reflects the development of the abdominal organs (such as liver + spleen)

29
Q

Are abdominal circumferences usually done correctly?

A

No, easily mismeasured

30
Q

Why is it important to measure an abdominal circumference correctly?

A

B/c it factors into fetal weight + health (rather than just an indicator of fetal age)

31
Q

Do abdominal circumferences include the skin?

A

Yes! Should be circular in shape + include the skin

32
Q

Best fetal position to obtain an abdominal circumference?

A

When baby is on its side

33
Q

Do the long bones get affected by fetal molding/position in the womb?

A

No

34
Q

Do tall parents typically have tall or short babies?

A

Tall, results in bigger estimations of size (not really seen in 1st trimester tho)

35
Q

What is the m/c error when imaging the long bones?

A

Being oblique + missing the ends of the bones

36
Q

All fetal limbs should be evaluated for what?

A

Symmetry

37
Q

Which long bone length is used for dating + growth?

A

Femur length

38
Q

How do we correctly measure the femur length?

A

-Only measure the shaft/diaphysis (don’t include the 2 epiphysis ends)
-Beam should be perpendicular to the shaft

39
Q

Should we measure the femur closest or farthest from the transducer?

A

Closest

40
Q

What tip can we use when looking for the humerus to measure, so we don’t accidentally measure the femur twice?

A

-The humerus closest to transducer is easiest to find in relation to head/spine
-Look for the bladder or another landmark when measuring the femur

41
Q

Which bone often gets mistaken for the femur?

A

Humerus (b/c have similar measurements)

42
Q

Is it common to measure distal extremities?

A

-No, except with achondroplasia (short limbed dwarfism)
-Always observe for symmetry

43
Q

Why would we measure the distal extremities?

A

-Help resolve conflict in age estimates

44
Q

In the forearm, is the radius or ulna larger?

A

Ulna

45
Q

Location of radius + ulna?

A

Radius: lateral, side where thumb is
Ulna: medial, side where pinky is (larger)

46
Q

If the fetal wrist/hand is rotated, will the ulna + radius be crossed or parallel?

A

Crossed

47
Q

In the lower leg, is the tibia or fibula larger?

A

Tibia

48
Q

Location of the tibia + fibula?

A

Tibia: medial, side of big toe
Fibula: lateral, side of pinky toe

49
Q

Why is an estimate of fetal weight important to tell the obstetrician?

A

To notify them of any developing problems + to assist in subsequent management of the pregnancy

50
Q

Which 2 measurements must we be extra careful when using for a weight estimate?

A

-Abdominal diameter
-Abdominal circumference

(there can be significant variation in weight estimates)

51
Q

How do we measure the fetal foot?

A

From the tip of the second toe (or longest toe) to the heel

52
Q

Why do we measure the foot?

A

Used for femur/foot ratios (b/c short femurs are associated with trisomy 21)

53
Q

Short femurs are associated with what?

A

Trisomy 21

54
Q

Which measurement is easily mismeasured?

A

Abdominal circumference

MIDS 187 (19 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions