E2: Fetal Assessment Flashcards
What is Antenatal Screening?
How does it differ from Prenatal diagnosis?
Antenatal screening is the process of identifying those at high risk of a disorder so they can be offered prenatal diagnosis. Prenatal diagnosis establishes whether or not the disorder is definitely present.
Thus, antenatal screening is step 1, while prenatal diagnosis is step 2.
What, in general, are the methods of fetal assessment discussed? (9)
- Uterine growth
- Fetal Movement Counting
- Non-Stress Test
- Contraction Stress Test
- Amniotic Fluid Assessment/Index
- Doppler Velocimetry
- Percutaneous Umbilical Blood Sampling
- BioPhysical Profile (BPP)
- Modified BPP
What is the general process behind Fetal Movement Counting?
What are the types of Fetal Movement Counting?
In Fetal Movement Counting, the fetus is monitored via transducer for 30 minutes to observe any of the described movements.
There are (3) Types of Fetal Movements that are counted;
- Gross Movement
- Fetal Tone
- Fetal Breathing Movements
Describe the type of fetal movements being observed in Gross Movement counting.
How are these movements scored?
In Gross Movement Counting, they are looking for discrete movement of the body or limb.
*These movements peak during week 32.
Score:
2/2: 3+ movements observed within 30m
0/2: <3 movements observed within 30m
Describe the type of fetal movements being observed in Fetal Tone counting.
How are these movements scored?
In Fetal Tone Counting, they are looking for both extension & flexion of an extremity (full cycle; i.e. opening & closing the hand).
Scoring:
2/2: 1 ext/flx cycle observed within 30m
0/2: Neither ext or flx observed within 30m
Describe the type of fetal movements being observed in Fetal Breathing Movements counting.
How are these movements scored?
While observing Fetal Breathing, they are looking for Rhythmic Paradoxical Chest movements associated with fetal respiration, lasting longer than 30s.
Scoring:
2/2: 1+ movements for 30s+ within 30m
0/2: No movements or duration is <30s
How is chest movement different in fetuses than in birthed humans during respiration?
When does fetal respiration primarily occur?
Chest movement is reversed in fetuses during respiration. That is, the chest wall collapses during inspiration and expands during expiration.
Fetal respiration primarily occurs;
- While Sleeping (0400-0700)
- Following breakfast (1000-1700)
Minimum from 2000-2400
Which method of assessment can be used at the earliest point in gestation?
Fetal Movement Counting @ 20W
Which Method of Assessment requires the longest waiting period to be used?
Contraction Stress Test @ 36W
Give the General Trend of initiation time for the Methods of Assessment from earliest to latest.
Earliest:
- Fetal Movement Counting @ 20W
- Doppler Velocimetery/Ultrasound @ 24W
- Fetal BPP @ 28W
- Modified BPP / NST @ 32W
- Constraction Stress Test @ 36W
Latest:
Describe the process of the Non-Stress Test and what is being tested/monitored.
How does the duration change if there is some variability in one of the aspects being monitored?
- Patient (mother) lies in a lateral tilt position
- External transducer monitors the Fetal HR & Uterine Activity for 20 minutes
- Simultaneously, the mother records movements by clicking a button, which is recorded on the record.
If there is variability found in the FHR, the duration can be extended up to 40 minutes.
Describe the process of the Contraction Stress Test and what is being tested/monitored.
Contraction Stress tests consists of;
- NST
- Uterine Contraction Test
Uterine Contraction Test procedures;
- Uterine Conctractions are induced via Oxytocin administration
- Alter dosage to achieve 3+ contractions lasting 40s+ over 10m
- These conditions MUST be met for the test to be interpreted
- Interpretation & Analysis
What are the potential results from the Uterine Contraction Test?
Negative: No late or significant Variable Decelerations
Positive: Late Decelerations following 50% or more of the contractions
Equivocal-Suspicious: Intermittent late decelerations or significant variable decelerations
Equivocal-Hyperstimulatory: FHR Decelerations occur in the presence of contractions more frequent than every 2m or exceeding 90s
Unsatisfactory: Fewer than 3 contactions in 10m or uninterpretable
Describe the process of the Amniotic Fluid Index.
In the AFI, the depth of the largest vertical pocket (free of fetal parts/cord) is measured.
Scoring:
2/2: 2cm+
0/2: <2cm
What is the fetal BioPhysical Profile?
What do the findings of this profile aim to identify?
The BPP consists of (5) Variables;
- (3) Fetal Movement variables visualized by US in real time
- Gross, Tone, & Breathing
- NST
- Amniotic Fluid Vol.
The aim of this profile is to reflect that the fetus can accelerate it’s HR, move appropriately, and is surrounded by adequate amniotic fluid. These suggest that the fetus is not hypoxic.
Taking into account the (5) variables in the BPP, what does a score of 10 indicate?
10/10: Normal, Nonasphyxiated fetus
No fetal indication for intervention
Taking into account the (5) variables in the BPP, what does a score of 8/10 indicate?
There are (2) interpretations of 8/10, which differ based on the Amniotic Fluid Vol (AFV).
8/10 w/ Normal AFV: Normal, nonasphyxiated Fetus
8/10 w/ Decreased AFV: Chronic Fetal Asphyxia suspected
Deliver the baby
