Antepartum - Fetal Surveillance & U/s

Front 1

When and how is nuchal translucency (NT) measured?

Back 1

Between 10-14 wks gestation with ultrasound

Front 2

What does increasing nuchal translucency mean?

Back 2

Increased odds of chromosomal abnormalities

20% when NT = 3.5-4.4 mm
50% when NT = 5.5-6.4 mm
75% when NT > or = 8.5 mm

Front 3

What is "first screen"?

Back 3

Combined 1st tri screen:
Nuchal translucency with serum screen
1) PAPP-A
2) Free beta-hCG

Front 4

What is the FASTER study?

Back 4

First and Second Trimester Evaluation of Risk (FASTER)

-87% detection of abnormalities
-5% false positive

Front 5

What is the Triple (Quad) Screen?

Back 5

Multiple marker assay

1) MSAFP, 2) estriol, 3) hCG, 4) Inhibin A

Front 6

What does the Triple (Quad) Screen test for?

Back 6

Screening for neural tube defects, Trisomy 18 & 21

Front 7

What are possible causes of elevated AFP levels?

Back 7

1) neural tube defects
2) esophageal or intestinal obstruction
3) liver necrosis
4) abdominal wall defects
5) kidney disorders
6) oligohydramnios
7) multifetal gestation
8) decreased maternal weight
9) underestimated fetal age

Front 8

What are some possible reasons for low AFP levels?

Back 8

1) chromosomal trisomies
2) gestational trophoblastic disease
3) fetal death
4) increased maternal weight
5) overestimated fetal gestational age

Front 9

What are the follow-up options for an abnormal screen?

Back 9

1) genetic counseling
2) ultrasound
3) amniocentesis
4) chorionic villus sampling

Front 10

What can an ultrasound tell you?

Back 10

1) dates
2) viability
3) anomalies

Front 11

What are the indications for ultrasound in 1st tri?

Back 11

1) check dating
2) confirm viability
3) evaluate pregnancy with vaginal bleeding
4) adjunct to chorionic villus sampling or early amnio
5) evaluate uterine mass or anomaly

Front 12

What findings do we expect from 1st tri ultrasound?

Back 12

1) Fetal #
2) Crown rump length --> estimated gestational age
3) location of sac
4) identify embryo
5) evaluate uterus and adnexa for mass, size, and shape
6) cardiac activity

Front 13

What are the indications for ultrasound in 2nd tri?

Back 13

1) accurate dating*
2) confirm viability*
3) evaluate pregnancy with vaginal bleeding
4) adjunct to traditional amnio
5) evaluate uterine mass or anomaly
6) screen for anomalies
7) fetal growth/EFW

Front 14

What are the indications for ultrasound in 3rd tri?

Back 14

1) dating?
2) fetal growth/EFW, number, presentation
3) placental location
4) follow-up for anomalies
5) confirm IUFD (intrauterine fetal demise)
6) 3rd tri procedures: a) ECV, b) amnio, c) BPP, d) PUBS

Front 15

What must an FNP do to request an obstetric US?

Back 15

1) identify woman
2) state indication for US
3) give necessary clinical data (maternal age, prima gravida, wks gestation from LMP, EDD)
4) request specific information

Front 16

When should women with low risk pregnancies begin fetal movement counting?

Back 16

from 34 to 36 wks

*decreased fetal movement requires follow-up!

Front 17

When should women with high risk pregnancies begin fetal movement counting?

Back 17

from 28 wks

*decreased fetal movement requires follow-up!

Front 18

What is a non-stress test (NST)?

Back 18

Observing FHR for 20 minute period looking for two accelerations (15 bpm for 15 seconds) above baseline

Front 19

What is a reactive NST?

Back 19

Two accelerations in 20 minutes

Front 20

What is a non-reactive NST result?

Back 20

Do not reach goal of two accelerations in 20 min

Front 21

What is an inconclusive NST result?

Back 21

Could not establish baseline FHR

Front 22

What are some reasons to order NST?

Back 22

1) decreased fetal movement
2) IUGR (h/o or in this pregnancy)
3) gestational DM
4) pre-existing DM
5) HTN/PIH, preeclampsia
6) multiple gestation
7) oligohydramnios
8) post-dates
9) PROM
10) Rh issoimunization
11) h/o IUFD

Front 23

What are the follow-up options for non-reactive NST?

Back 23

1) Prolonged NST*
*observe FHR for another 20 min
2) CST (contraction stress test)*
3) BPP
4) induction of labor (IOL)

Front 24

What is the Contraction Stress Test (CST)?

Back 24

Presence or absence of decelerations with uterine contractions

Front 25

What is necessary for a CST?

Back 25

3 contractions lasting 40 seconds each in 10 min

Front 26

What is the follow-up for a negative CST?

Back 26

weekly evaluation for uteroplacental insufficiency (UPI) screening

Front 27

What is the follow-up for a positive CST?

Back 27

1) BPP or repeat CST in 24 hrs or IOL
2) depends on clinical picture

Front 28

What is the follow-up for an equivocal CST?

Back 28

BPP or repeat CST in 24 hrs

Front 29

What are the contraindications to CST?

Back 29

1) pre-term labor or risk for PTL
2) PROM
3) h/o uterine surgery or classical c-section
4) placenta previa

Front 30

What are the components of the BPP?

Back 30

Uses US and external fetal monitoring to evaluate
1) fetal heart rate (NST)
2) fetal breathing movements
3) fetal movement
4) fetal tone
5) amniotic fluid volume

Front 31

How is the BPP scored (measured)?

Back 31

Each component (FHR, fetal breathing, FM, fetal tone, AFV) is scored a maximum of 2 pts if criteria is met

-possible 10/10

Front 32

What are the indications for BPP?

Back 32

1) abnormal NST or CST
2) IUGR (known or suspected)
3) diabetes
4) preeclampsia
5) multiple gestation
6) post-dates

Front 33

What is the follow-up for BPP within normal limits?

Back 33

repeat weekly or twice weekly for BPP with > or = 8/10 with normal amniotic fluid volume (AFV)

Front 34

What is the follow-up for equivocal BPP?

Back 34

repeat BPP in 24 hrs or IOL for BPP 6/10 with normal AFV

Front 35

What is the follow-up for BPP when the fetus is at high risk for asphyxia?

Back 35

1) 6/10 with abnormal AFV --> repeat BPP in 24 hrs or IOL
2) 8/10 with abnormal AFV --> repeat AFV in 24 hrs?

Front 36

What is the follow-up for BPP with high risk or certain asphyxia?

Back 36

High risk or certain asphyxia: < or = 4/10

Intervention: IOL

Front 37

What is Amniotic Fluid Index (AFI)?

Back 37

Total AFI equals the depth (in cm) of the amniotic fluid in all 4 quadrants
--> assessed with US

Normal range: 5-20 cm

Front 38

What does doppler velocimetry measure?

Back 38

Decreased diastolic flow in umbilical artery in growth restricted fetus

Front 39

What is the indication for doppler velocimetry?

Back 39

diagnosis of IUGR

Front 40

What are abnormal flow studies (i.e., doppler velocimetry) associated with?

Back 40

1) fetal hypoxia and acidosis
2) increased perinatal morbidity and mortality

Front 41

What chromosomal abnormalities of the fetus does nuchal translucency detect?

Back 41

Trisomies 13, 18, and 21

Front 42

What are PAPP-A and beta-hCG?

Back 42

Maternal biomarkers -- high levels denote increased risk

Front 43

How effective is the combined 1st trimester screen at detecting chromosomal abnormalities?

Back 43

detection of 87% of fetuses born with chromosomal abnormalities

Front 44

When is the optimal time to perform a combined first tri screen?

Back 44

12-13 wks gestation

Front 45

When is the optimal time to perform a triple (quad) screen (hint: 2nd tri)?

Back 45

15-16 wks gestation

Front 46

What biomarker is used in the triple (quad) screen that is not available with combined 1st tri screening?

Back 46

MSAFP (maternal biomarker) -- screens for neural tube defects

Front 47

What is the detection rate for neural tube defects with triple/quad screen?

Back 47

80%

Front 48

How does the combination of 1st and 2nd tri screening increase detection?

Back 48

combined results of the two screens give a detection rate of 90-94%

Front 49

How does the sequential screen work?

Back 49

1. Risk assessment is given after the 1st tri screen
2. Revised risk assessment is given after the 2nd tri screen

Front 50

What is the integrated screen?

Back 50

1. Lab holds on to the results after 1st tri screen
2. After 2nd tri testing, 1st tri results are integrated with 2nd tri results and one result is given to patient
**better detection rate

Front 51

What is the stepwise screen?

Back 51

1. If results from 1st tri screen indicate low risk, no 2nd tri screening is performed
2. Moderate risk: patient receives 1st tri results and then undergoes 2nd tri screen and gets those results
3. High risk: referred for diagnostic testing after receiving 1st tri results

Front 52

Who should genetic counseling be offered to?

Back 52

offer to al patients with abnormal results -- briefly discuss options and provide referral

Front 53

How can an ultrasound help if results indicate risk of chromosomal abnormality?

Back 53

US may provide addt'l information on how fetus is affected by the abnormality

Front 54

How is amniocentesis used as follow-up for abnormal screening results?

Back 54

Diagnostic tool

Front 55

Can amniocentesis detect any abnormality/disorder?

Back 55

NO, it can only test for what is known. Order for amnio should specify what lab is looking for (e.g., family hx of known disorder)

Front 56

When is amniocentesis optimallly performed?

Back 56

14-16 wks gestation

Front 57

At the time of amniocentesis what can be done to screen for neural tube defects?

Back 57

AFP (biomarker) can be collected

Front 58

How is chorionic villus sampling used when there are abnormal screening results?

Back 58

diagnostic tool

Front 59

When should chorionic villus sampling occur?

Back 59

11-14 wks gestation

--> risk of fetal truncation if performed too early

Front 60

What is the disadvantage of chorionic villus sampling?

Back 60

cannot screen for neural tube defects

Front 61

How is US used as a screening tool?

Back 61

1. presence of FHR to dx pregnancy
2. nuchal translucency testing
3. sex of the fetus (20 wks gestation) + screening for fetal anatomy (all organs should be fully formed)

Front 62

How is US used as a diagnostic tool?

Back 62

craniofacial deformities, cardiac defects, etc.

*can detect but cannot give reasons for defects

Front 63

How does US allow you to determine gestational age?

Back 63

allows for measurement of crown-rump length (CRL) to determine EGA*

*if difference between dating from LMP and US is >1 week, most practices will change gestational age and EDD to that calculated by US

Front 64

When is US used in 3rd tri procedures?

Back 64

1. external cephalic version (ECV) -- helps trained MD rotate fetus to cephalic presentation
2. BPP
3. percutaneous umbilical blood sampling (PUBS)

Front 65

How should a woman monitor fetal movement counting (FMC)?

Back 65

1. any kind of movement should be counted
2. should count for 1 hour, feeling for 5-10 movements per hour

Front 66

What should a woman do if she does not feel 5-10 fetal movements in an hour or the number has decreased from previous counts?

Back 66

1. If number of movements not met in first hour, count for a second hour
2. If second hour is still low, contact physician
--> decreased FMC should be addressed by physician

Front 67

What is a reactive NST?

Back 67

2 accelerations in 20 minutes

Front 68

What is an inconclusive NST?

Back 68

Too much variability to determine accelerations, requires retest

Front 69

What are the follow-up options for non-reactive NST?

Back 69

1. prolonged NST: up to 40 min --> is reactive if you can find 20 min window in that time in which 2 accelerations occur
2. Contraction stress test (CST)

Front 70

What is the CST and how is it administered?

Back 70

1. Tests for presence or absence of decelerations with uterine ctx
2. Low level of pitocin is administered to cause 3 ctx that last for 40 seconds in 10 min window

Front 71

For which patients is CST contraindicated?

Back 71

1. patients at risk for PTL
2. patients with h/o c-section

Front 72

What is oligohydramnios?

Back 72

<5 cm of amniotic fluid (as measured by AFI)

Front 73

What is polyhydramnios?

Back 73

>20 cm of amniotic fluid (as measured by AFI)

Front 74

What is the purpose of doppler velocimetry?

Back 74

ensure that blood flow into fetus is always positive