Antepartum Fetal Surveillance
‘HELLO BABY, HOW ARE YOU?’
Presented By: Janet L. Smith, RNC, BSN
Author: Ruth Saathoff, RNC, BSN
OBJECTIVES:
At the end of this class the learner will be able to:
 Name 5 methods of monitoring the fetus for wellbeing
 Describe the physiology of maternal and fetal
circulation in the relationship to fetal reserve.
 Identify the maternal and fetal conditions that
indicate a need for fetal surveillance.
Indications for Fetal Evaluation
 Maternal risk factors




Pre-existing maternal disease
Exposure to teratogens in 1st trimester
Substance abuse
Infertility or conception within 3 months of last
delivery
(cont.)
Indications for Fetal Evaluation
 Maternal Factors (cont)

History of OB complication
• Oligohydramnios, Gestational Hypertension, etc.




Previous pregnancy loss
PROM > 24 hours
Familial history of genetic abnormality
Post dates
Indications for Fetal Evaluation
 Fetal risk factors







Prematurity
SGA or LGA
Intrauterine growth restriction (IUGR)
Known anomaly
History of IUFD
Fetal cardiac arrhythmias
Decreased fetal movement
Why and When
 Why do we think of a well baby in terms of
placental perfusion?



Oxygen & nutrients are needed for fetus
Risk factors may reduce delivery to fetus
Good oxygen & nutrient delivery results in movement
and growth
 When is surveillance started?



When risk is present
IDDM (type 1) - 32 weeks
Previous loss - 34 weeks
Patient: Kay Sarah
Doc: I. Ben Cursed M.D.




G 2 P1-0-0-0
Previous stillbirth @ 39 weeks
Present gestation is 37 weeks
Has been keeping a Fetal Activity Diary
(FAD) since 36 weeks
 Now to begin surveillance with weekly
NST
Fetal Movement Counts
 FM indicator of intact Central Nervous
System function
 First line defense to identify the fetus in
trouble
 30-50% of IUFD occur in women with
no identifiable risk factors
 FAD
Methods for Fetal Movement
Counts
 Count-to-ten
 Counting after meals
 Evening monitoring
Interpretation
 Report when criteria not met
 Report no movement over 8 hours
 Report sudden violent increase in fetal
activity followed by cessation of
movement
 Report changes in normal pattern of
fetal movement
Non-stress Test (NST)
 Fetal movement typically accompanied
by FHR accels when CNS intact and
with adequate oxygenation
 Procedure:



Position sitting, semi-Fowler’s with tilt to
either side
Good quality EFM tracing for 20-40 min
May monitor up to 60 min
Interpretation
 What to look at (5 parameters)





What’s the baseline?
Is there variability present?
Any uterine activity present?
Any accels present?
Any decels present?
 Assessment
Baseline
Variability
Accelerations
Uterine Activity
Decelerations
Fetal Movement
Interpretation
 Reactive: 2 accels in 20 min. 15 bpm X
15 sec.



15 sec. from start of accel to end of accel
15 bpm at apex of accel
gestation < 32 weeks
• 10 bpm X 10 sec.
• frequent decels of 10-20 sec.
Interpretation
 Nonreactive: does not meet above
criteria


if not reactive in 60 min. unlikely to become
so; call HCP
isolated decels seen in as many as 33%
Example at term
Example 31 weeks
Back to Ms. Sarah
 Her NST is reactive
 Anything else?




Chart the 5 parameters on strip & chart
Call HCP and report
Schedule next appointment
Continue FAD
Retesting
 If no risk factors, unlikely to have FD in
one week
 With risk factors, repeat 2 times a week
 If pregnancy status changes, repeat in
24-48 hours
Patient: Ms. Hertzelot
Doctor: I. Ben Cursed M.D.




37 weeks gestation
G1 P0
Has not felt baby move for 8 hours
Please do NST
Assessment
 NST: Non-reactive after 40 min
 Possible causes:





fetal sleep
smoking before coming
Maternal medications
immature CNS
fetal hypoxia
Well, now what?
 Juice myth
 Do Fetal Acoustic Stimulation Test
(FAST)





Usually elicited after 28 weeks
Can be done after 10 min of non-reactive
pattern
Handheld device generates a low frequency
(82 decibels) vibro-acoustic stimulus
Apply for 3-5 sec avoiding fetal head; may
repeat X 2 at least 1 min apart
May cause some level of stress
Results of FAST
 Causes ‘Moro’ or startle reflex if CNS
intact
 Increase in FHR


1 accel of 15 bpm over 2 minutes
2 accels of 15 bpm for at least 15 sec within
5 minutes of test
 Useful way to reduce number of nonreactive NST's
 Shortens testing time
Vibroacoustic
Stimulation
Back to Ms. Hertzelot
 Well, now what?




NST reactive with FAST
Monitor until BL is restored
Home with FAD
Document on Strip and Chart
Patient: Ms. Shirley I. M. Late
Doctor: I Ben Cursed M.D.
 40 & 5/7 weeks gestation
 Please do NST
 Results:



NST: non-reactive
FAST (or VAS): still non-reactive
More monitoring: still non-reactive
Well, now what?
 Options:

Contraction Stress Test (CST)
• assumes uteroplacental insufficiency will show
hypoxia with late decels with contractions

Biophysical Profile (BPP)
• Ultrasound assessment of acute and chronic
markers show good predictor of fetal well-being
CST
 Modes

Nipple stimulation (BST)
• may be poorly received by patient
• noninvasive

IV oxytocin (OCT)
• requires invasive procedure

Spontaneous contractions
Interpretation
 FHR response to stress of contractions

3 contractions lasting 40-60 sec. in 10 min.
 ‘Negative’ is absence of late decels (That’s good!)
 ‘Positive’ is presence of late decels (That’s bad!)

> 50% of contractions--need to deliver
 ‘Equivocal’ is presence of some lates

<50% of contractions
 Hyperstimulation or Unsatisfactory Results

Considered testing failure and are not clinically useful
 ‘Suspicious’

Variable Decelerations
Negative
Positive – Late Decelerations
Suspicious – Variable Decelerations
Test Failure - UterineTachysystole
BPP
 Parameters





Fetal Tone (FT) (7-8wks)
Fetal Movement (FM) (9wks)
Fetal Breathing Movements (FBM))
Amniotic Fluid Index (AFI) > 6 cms
NST (Accelerations 30-32 wks)
 Need high tech equipment/skilled
technician
 Non-invasive, highly predictive
(20-21wks)
Scoring
Biophysical
Variable
Fetal breathing
movements
Normal
(Score = 2)
1 or more episodes of ≥ 20 s within 30 min
Abnormal
(Score = 0)
Absent or no episode of ≥ 20 s within 30
min
Gross body movements
2 or more discrete body/ limb movements
<2 episodes of body/limb movements
within 30 min (episodes of active
within 30 min
continuous movement considered as a single
movement)
Fetal tone
1 or more episodes of active extension with
return to flexion of fetal limb(s) or trunk
(opening and closing of hand considered
normal tone)
Slow extension with return to partial
flexion, movement of limb in full
extension, absent fetal movement, or
partially open fetal hand
Reactive FHR
2 or more episodes of acceleration of ≥ 15
bmp* and of >15 s associated with fetal
movement within 20 min
1 or more episodes of acceleration of fetal
heart rate or acceleration of <15 bmp
within 20 min
Qualitative AFV
1 or more pockets of fluid measuring ≥ 2 cm Either no pockets or largest pocket <2 cm
in vertical axis
in vertical axis
Interpretation
 Scoring





10 point scale (if performed with a NST)
8-10 indicates fetus in good condition
6 indicates need to repeat in 4-6 hours
<6 indicates need for delivery
AFI < 6 cms indicates delivery
Back to Ms. Late
 Well, now what?






NST: non-reactive
CST: negative
BPP: 6/10 (FT-2, FM-2, FBM-0, AFI-2,
NST-0)
Report to HCP/document all findings
Home with FAD
Reschedule for repeat NST/BPP in 2-3 days
Other Surveillances
 Amniocentesis


Fetal lung maturity
Testing- genetic, cultures, change in
optical density
 Ultrasound Examination



Uterine contents
Fetal biometry / dating
Fetal anatomic examination
Other Surveillance Options
 Doppler Flow Studies


Checks BP of uterine and placental vessels
Associated with fetal growth deficiency
Other Surveillance Options (cont’d)
 Chorionic Villus sampling

early prenatal genetic studies
 References:
American Academy of Pediatrics, American College of Obstetricians &
Gynecologists, Guidelines for Perinatal Care (5th ed. 2002), Antepartum
surveillance, pp. 89-107.
AWHONN Fetal Heart Rate Monitoring Principles and Practices 4th Ed.
Christensen FC, Olson K, Rayburn WF (2003). Cross-over trial comparing
maternal acceptance of two fetal movement charts. Journal of Maternal-Fetal
and Neonatal Medicine, 14(2), pp. 118-122.
Devoe, L, Glob. libr. women's med.,
(ISSN: 1756-2228) 2008; DOI 10.3843/GLOWM.10210
Martin, E.J., Intrapartum Management Modules (3rd ed. 2002), Performing fetal
surveillance testing, pp. 411-413.
Mattson, S., Smith, J.E., Core Curriculum for Maternal-Newborn Nursing (3rd.
ed.,2004), Clinical practice pp. 165-166.
Simpson, K. R., Creehan, P.A., Perinatal Nursing (2nd ed., 2001), Fetal
surveillance, pp. 147-154.