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Flashcards in Antepartum Assessment Deck (47):
1

When/why is the first ultrasound in pregnancy?

7 wks- confirm pregnancy, exclude ectopic or molar pregnancy, confirm cardiac pulsation, crown-rump length (dating)

2

When/why is second ultrasound in pregnancy?

18-20 wks
Look for congenital malformations, verify dates/growth, placental position

3

When/why is third ultrasound in pregnancy?

34 wks
Evaluate fetal size, assess fetal growth, verify fetal position

4

What/when can you see on early ultrasounds?

4.5 wks- gestational sac
5 wks- yolk sac
5.5 wks- embryo
6-7 wks- heartbeat and blood flow
7-13 wks- crown-rump length
13 wks- biparietal diameter
14 wks- femur length

5

What measurements are used for dating/ how accurate are they?

CRL (early first tri) +/- 4.7 days
BPD/HC/AC/FL up to 22 wks +/- 1wk
^ up to 30 wks +/- 2wks
After 30 wks +/- 2-3wks

6

When are EFW and growth scans done?

If fundal ht lags/exceeds EGA by EDD

*accuracy is low
HC/AC ratio is good predictor for IUFGR

7

What is the only caution with ultrasound?

Can increase body temperature
(Significant only for long exposure time)

8

When is a NST considered reactive?

2 access in 20 minute period, 40 minute max testing, plus normal baseline and moderate variability

9

What do you need to know about vibroacoustic stimulation?

Sound stimulus applied for 3 seconds
Reactive accel correlates with nonacedemic fetus
Decreased effect in preterm or once ruptured

10

What do you need to know about scalp stim?

Rule out metabolic acidemia
Not to fontanels
Done between contractions
Accel good predictor of non-acidemic
Lack of accel poor predictor of acidemic

11

What do you do if you get a non reactive NST?

BPP or CST

12

What is a CST?

3 ctx in 10 minutes with oxytocin or nipple stim

13

What are the possible results of CST?

Negative- no late decels
Positive- recurrent lates
Suspicious- intermittent lates or variables
Unsatisfactory- poor tracing or not 3 ctx

14

What do you do if you get a nonreactive negative CST?

Repeat in 24 hrs

15

What do you do if you get a positive CST?

BPP, consider delivery

16

What do you do if you get a suspicious or unsatisfactory CST?

Repeat in 24 hrs

17

What are the components of a BPP/ when do they develop?

Fetal tone (7-8wks)
Fetal movement (9wks)
Fetal breathing movements (20-21wks)
Reactive NST (28-32wks)
Qualitative AFV

18

What is a score of 2 for fetal breathing movements in a BPP?

1 or more episodes >30 seconds within 30 minutes

19

What is a score of 2 for gross body movements in a BPP?

3 or more limb/body movements within 30 minutes

20

What is a score of 2 for fetal tone in a BPP?

1 or more episodes of extension/return to flexion of limbs or trunk (or open/close of hands)

21

What is a score of two for qualitative AFV in a BPP?

1 or more pockets of fluid measure 2 or more cm

22

What is each parameter of a BPP regulated by?

CNS
first to appear, last to disappear with fetal asphyxia

23

How does ultrasonography work/ what is it used for?

Used by sound waves
Used to date, anatomy of fetus, examine placenta and amniotic fluid
Also used to assist in procedures (ie amnio)

24

What is the interpretation/follow up for a BPP score of 8 or 10?

Normal, low risk for chronic asphyxia
Repeat weekly or 2x/wk

25

What is the interpretation/follow up for a BPP score of 4-6?

Suspect chronic asphyxia
If 36wks or >, deliver
If under 36wks repeat in 4-6hrs

26

What is the interpretation/follow up for a BPP score of 0-2

Abnormal; strongly suspect chronic asphyxia
Deliver

27

How do you measure AFI?

Measure largest pockets of fluid (without cord) in each quadrant

28

What is a normal AFI at term?

7-20cm

29

How is oligo or poly diagnosed?

AFI 95th percentile for EGA

30

Why does oligo sometimes mean chronic hypoxia?

Fetus spares head heart and adrenals
Kidneys poorly perfused
Dec urine output

*takes about 13 days for AFI to go from normal to oligo with fetal compromise

31

What is a modified BPP?

NST plus AFI
Reactive and at least 5cm

32

What is the most common expectation with fetal movement counts?

10 movements in 2 hrs

33

What should you know about umbilical artery Doppler velocimetry ?

Uses ultrasound
Measures velocity of blood flow in umbilical artery

During systole flow is high
During diastole flow slows down *should not stop

34

What is an amniocentesis?

Small spinal needle inserted transabdominally to collect amniotic fluid sample under ultrasound

Sample used for genetic testing, assessment of fetal lung maturity, other testing

Can be used to reduce fluid with poly

Done after 15 wks

35

What is chorionic villus sampling?

Sample of placental villi at 10-13 wks
Obtained by inserting catheter transcervically
Tested for genetic disorders

36

What is cordocentesis?

Also called percutaneous umbilical cord blood sampling

Umbilical vein punctured for blood sample

Used to test for genetic and blood disorders

Largely replaced by placenta biopsy

37

How do you test fetal lung maturity?

Usually require amniocentesis

FLM or TDx
If FLM immature, then L/S ratio done
PG can be done with L/S ratio to inc reliability

38

What is trisomy 21?

Down syndrome
Mental retardation, facial abnormalities

39

What is trisomy 18?

Edwards syndrome
Median lifespan 5-15 days
Heart, kidney, internal organs anomalies

40

What is the first trimester genetic screening?

Detects inc risk of trisomy 21
Ultrasound measures nuchal translucency
Maternal serum measurements (PAPP-A, hCG)

Inc NT, inc hCG, dec PAPP-A predict trisomy 21

41

What is 2nd trimester genetic screening?

Detects trisomy 18, trisomy 21, and NTD's

Most common is quad screen:
Alpha fetoprotein (AFP)
hCG
Unconjugated estriol (uE3)
Inhibin A

Trisomy 18- AFP, uE3, hCG all dec
Trisomy 21- AFP, uE3 dec, hCG, inhibin A inc
NTD's - AFP inc

42

Black

Sickle cell

43

Jews

Tay-Sachs, Canavan disease

44

Cajuns

Tay-Sachs

45

French Canadians

Tay-Sachs

46

Mediterranean

Thalassemia

47

Southeast Asians

Thalassemia