intarpartum dfertal suveillance and anterpartum

1. FETAL SURVEILENCE AND
INTRAPARTUM FETAL MONITORING
Philippe BAZAMBANZA
ECSACOG RESIDENT
Supervisor: DR RUKUNDO JD, Obs&Gyn specialist,
MFM fellowship
13 OCT 2023

2. Objectives
After this presentation we will be able to
• To describe the goals of antenatal surveillance
and intrapartum monitoring
• To describe the antenatal surveillance and
intrapartum fetal monitoring
• To describe the indication of fetal surveillance

3. SCOPE OF PRESENTATION
• Introduction
• Indications for fetal surveillance
• Fetal assessment techniques
• Intrapartum fetal monitoring

4. Introduction
• Antenatal surveillance techniques use the biophysical profile
that includes fetal heart rate, breathing, movements and
amniotic fluid production.
• The main goal of antenatal surveillance to prevent fetal death
and avoidance of unnecessary interventions.
• Fetal surveillance techniques include, non stress test,
contraction stress test, biophysical profile, Fetal movement
,modified biophysical profile and Doppler velocimetry.

5. Cont’
• Intrapartum surveillance use CTG to monitor the fetal well
being during labor and to prevent birth asphyxia.
• The CTG has two functions: monitoring fetal heart rate
pattern and contractions

6. A. INDICATIONS FOR FETAL
SURVEILLANCE
• The ACOG suggests antepartum testing for pregnancies in
which the risk of antepartum fetal demise is increased, which
ACOG has defined as a stillbirth rate greater than 0.8 per 1000
High risk pregnancy:

7. Cont’
• Pre-gestational or gestational Diabetes
• Hypertensive disorders during pregnancy
• Fetal growth restriction
• Twin pregnancy
• Post term pregnancy
• Alloimmunization
• Systemic lupus erythematosus

8. Cont’
• Antiphospholipid antibody syndrome
• Sickle cell disease/ hemoglobinopathies other than Hb SS dse
• Decreased fetal activity
• PPROM
• Oligohydramnios or polyhydramnios
• Prior fetal demise
• Other indications: maternal heart disease, maternal vascular ,
renal disease – Cr >1.4mg/dl, uncontrolled hyperthyroidism,
non immune hydrops, cholestasis, Abnormal serum markers:
PAPP-A <5th percentile
Indication for outpatient Antenatal Fetal
surveillance: ACOG comitee option, number
828. Obst Gynecol 2021;137:e177

9. Cont’
• Epidemiologic data suggest a small/Low
increased risk of fetal demise associated with
a number of additional conditions, including:
• Advanced maternal age. >35years
• Obesity. BMI > 40
• Major fetal structural anomalies:
Diaphragmatic hernia,…
• Abnormalities in first- and second-trimester
maternal biochemical trisomy 21 (Down
syndrome) screening results .
Goetzl L. Adverse pregnancy outcomes after abnormal first-
trimester screening for aneuploidy. Clin Lab Med 2010;
30:613.

10. 1.Fetal movement counting
• Fetal movement starts as early as 7 weeks and become
coordinated by the end of pregnancy .
• Maternal perception of fetal movement typically begins in the
second trimester at around 16 to 20 weeks of gestation and
occurs earlier in parous patients than nulliparous patients.
The mother's first perception of fetal movement, termed
"quickening," is often described as a gentle flutter.
• Between 20 to 30 weeks the body movement becomes
organized and fetus starts to show rest-activity cycle .
• As pregnancy advances fetal movements decreases due to
declining amniotic fluid and space
Gillieson M, Dunlap H, Nair R, Pilon M.
Placental site, parity, and date of quickening.
Obstet Gynecol 1984; 64:44.

11. Clinical implication
• Transient decreases in fetal activity can be due to
fetal sleep states, maternal medications that cross
the placenta (eg, sedatives), or maternal smoking.
• Sleep cycles may last up to 40 minutes
• Decreased fetal activity may be the sign fetal
hypoxemia
• Perception of least 10 fetal movements (FMs) over
up to two hours when the mother is at rest and
focused on counting ("count to 10" method), is
normal.
Pillai M, James D. The development of fetal
heart rate patterns during normal pregnancy.
Obstet Gynecol 1990; 76:812.

12. 2.Contraction stress testing
• Contraction stress test is performed by infusion
of oxytocin to induce contractions or nipple
stimulation
• Induction is continued until there 3 uterine
contractions for 10 minutes
• If uteroplacental pathology is present , these
contractions elicit late decelerations.
• Contractions also may produce a pattern of
variable decelerations(due to cord compression,
or placenta insufficiency)

13. Interpretation of contraction stress
test
• Positive – A positive (abnormal) test has late decelerations
following ≥50 percent of contractions. The test is positive even if
the contraction frequency is less than three in 10 minutes.
• Negative – A negative (normal) test has no late decelerations or
significant variable decelerations.
• Equivocal – An equivocal-suspicious test has intermittent late
decelerations or significant variable decelerations, while an
equivocal-tachysystolic has decelerations with contractions
occurring more frequently than every two minutes or lasting longer
than 90 seconds.
• Unsatisfactory – An unsatisfactory test has fewer than three
contractions in 10 minutes (and is not positive as defined above), or
is uninterpretable for other reasons.
Antepartum Fetal Surveillance: ACOG Practice Bulletin, Number 229. Obstet
Gynecol 2021; 137:e116.

14. 3.Non stress test
• This test involve the use of doppler to detect
the fetal heart accelerations as the fetal
moves
• In 1970s the non stress test became the
primary method for testing the fetal health.
• Non stress test is easier to perform
• It is mostly used nowadays for assessment of
fetal well being and is also part of BPP.

15. Normal non stress test
• This test is noninvasive and can be performed
in any settings with electronic fetal monitor.
• No risk for maternal or fetal injury
• NST is typically started after 28 weeks where
fetal neurological maturity enables heart rate
accelerations

16. Reactive NST
• NST is reactive if there are 2 or more FHR
accelerations reaching peak of at least 15
beats/min above base line, lasting 15 seconds
in period of 20 min
• This reactive test is when the fetus is greater
than 32 weeks
• This implies a well oxygenated fetus
Brown R, Patrick J. The nonstress test: how
long is enough? Am J Obstet Gynecol 1981;
141:646.

17. NST
• Prior to 32 weeks gestation, a reactive NST is
defined as 2 accelerations that rise at least 10
beats/min above base line lasting for 10
seconds in 20 min
• If NST is reactive with decelerations,
sonographic evaluation should be done to
look for associated factors (oligohydramnios,
IUGR, cord compression)
Antepartum Fetal Surveillance: ACOG Practice
Bulletin, Number 229. Obstet Gynecol 2021;
137:e116.

18. NST
• Variable, late, or prolonged decelerations
observed during antepartum testing require
further evaluation:
• extended FHR and uterine activity monitoring,
ultrasound assessment of fetal growth and
anatomy, BPP, amniotic fluid volume, and/or
Doppler velocimetry in the setting of fetal
growth restriction.

19. Non reactive NST
• Non reactive test implies NST that does not
meet accelerations criteria for reactive NST
• Monitor should be done at least 40 min to
conclude a Non reactive NST.
• It is the sign of impaired fetal oxygenation and
possible metabolic acidemia or a sleep pattern

20. Non reactive NST
• Possible causes include: prematurity, fetal
sleep cycle, maternal smoking, sepsis, cardiac
anomalies, or maternal ingestion of drugs with
cardiac effect.
• Test can be repeated in 30 to 40 min,
vibroacoustic stimulation.
• Perform a back-up test, (either CST or
complete BPP) to distinguish false positive
non reactive NST to fetal hypoxemia.
Antepartum Fetal Surveillance: ACOG Practice
Bulletin, Number 229. Obstet Gynecol 2021;
137:e116.

21. 4.Fetal biophysical profile
• It is a non invasive, easy to learn and to be
performed
• It uses US to assess the fetal biophysical
parameters
• These parameters include fetal breathing, fetal
tone, fetal movements and amniotic fluid
volume

22. BPP
• These parameters are regulated and
controlled by defined centers in the brain.
• These centers are sensitive to both local
factors and feedback from peripheral sensors.
• Abnormal biophysical activities are due to
neuronal suppression from hypoxemia,
acidemia, and ischemia

23. Table of BBP and interpretation
2 cm 2 cm

24. Modified BPP
• Modified BPP has been developed to reduce
the time taken for complete testing and
involve some component of BPP that are
predictive of good outcome.
• These components are NST and amniotic fluid
volume
• These are predictors of long term fetal well
being

25. Modified BPP
• About 90% of pregnancies that undergo
modified BPP have normal results and the rest
will need full BPP evaluation.
• You do complete BPP if this one is abnormal.

26. Factors that affect BPP score
• Antenatal corticosteroids, Mag sulphate
• Subclinical infection
• Preterm labor
• Fasting/hypoglycemia
• Transplacental passage of a substance that
causes general suppression of brain activity,
such as a sedative, opioid, or alcohol.
Tan KH, Sabapathy A. Maternal glucose
administration for facilitating tests of fetal
wellbeing. Cochrane Database Syst Rev 2012;
:CD003397.

27. Interpretation
• The normal score (10/10, 8/8, or 8/10) — A BPP of
10/10, 8/8, or 8/10 with normal amniotic fluid volume
is a normal score, a powerful predictor of normal fetal
acid-base status
• 8/10 because of oligohydramnios — Oligohydramnios
as the only abnormal variable in a BPP score is a rare
finding in the absence of membrane rupture or fetal
urinary tract anomaly, but may occur in postterm
pregnancies and pregnancies complicated by fetal
growth restriction. Management of oligohydramnios
depends on the clinical scenario

28. • The very abnormal score and abnormal score
(0/10, 2/10, 4/10)
• A BPP of 0/10 is a fetal emergency and carries
always an indication for prompt delivery if the
gestational age is sufficiently advanced to sustain
extrauterine life.
• A BPP of 2/10 is very abnormal and is virtually
always an indication for prompt delivery if the
gestational age is sufficiently advanced to sustain
extrauterine life.
• A BPP of 4/10 is also very abnormal

29. Oligohydramnios :
• In a fetus with intact membranes and a functional patent
genitourinary tract, a score of 4/10 with oligohydramnios is usually
an indication for delivery if the gestational age is sufficiently
advanced to sustain extrauterine life.
• Normal amniotic fluid – A score of 4/10 with normal amniotic fluid
is usually an indication for delivery if the gestational age is
sufficiently advanced to sustain extrauterine life. Before 34 weeks
of gestation, it is reasonable to administer a course of antenatal
corticosteroids and repeat the BPP 24 hours after the previous BPP;
delivery is indicated if the repeat BPP is 6/10 or less.

30. 5.Doppler US for fetal surveillance
• It is a non invasive procedure that assess the
fetal circulation in clinical conditions.
• It is used for studying major fetal circulation
systems(umblical artery, vein, aorta, middle
cerebral arteries)
• Use of fetal umbilical artery doppler is an
effective test for improving perinatal mortality
and morbidity.

31. • It improves understanding of fetal circulation
and fetal hemodynamic status.
• Each vessel has a unique blood flow velocity
waveform (FVW).
• Commonly used computed ratios include:
the ratio of systolic to diastolic blood flow
velocity (S/D), the pulsatility index (PI),
and the resistance index (RI) (Fig. 18-1).

32. Factors that affect the wave form
• gestational age- end diastolic velocity
increases with advanced age
• Fetal heart rate- if FHR are in normal
range(120-160) no change in Doppler indices
• fetal breathing and hiccups
• Fetal movement
• Technical factors (maternal obesity,
oligohydramnios, crowding in multiple
gestations)

33. Normal Umbilical artery Pattern
• Progressive increase in diastolic flow after 18
weeks gestation
• Decreasing S/D ratio over course of pregnancy
• Normal < 3.5 preterm and < 2.5 term

34. Image normal wave form

35. UA Doppler

36. Umbilical artery wave patterns
Elevated S/D
High resistance
Elevated S/D
High resistance

37. Umbilical artery wave patterns
High resistance to flow

38. Absence of end-diastolic flow velocities (AEDV) is depicted here (vertical arrows). As
noted in the text, this is an ominous sign associated with adverse perinatal outcome. The
upper portion of the image shows color Doppler guided interrogation of the umbilical
artery. The lower portion shows spectral Doppler waveforms from the umbilical artery.
Courtesy of Dev Maulik, MD, PhD.
© 2023 UpToDate, Inc. and/or its affiliates. All Rights Reserved.
Umbilical artery wave patterns

39. Umbilical artery wave patterns
Reverse end-diastolic
flow
Associated with obliteration of
>70% of placental arteries
Robert K. Creasy, MD; Creasy and Resnik’s Maternal-Fetal Medicine
principles and practice, seventh edition

40. Umbilical artery wave patterns
Spectral Doppler waveforms from the umbilical artery show reversal (arrows)
of end-diastolic flow velocities (REDV). REDV is a preterminal sign.
Courtesy of Dev Maulik, MD, PhD.
Graphic 116297 Version 1.0
© 2023 UpToDate, Inc. and/or its affiliates. All Rights Reserved

41. Interpretation of UA Doppler indices
• Quantitative interpretation — An S/D ratio >3.0 or RI
>0.6 at ≥28 weeks of gestation is the best single point
threshold for identifying pregnancies at high risk of
adverse outcomes and is used by many clinicians.
• Another common approach is to use the gestational
age-specific percentile distribution of the Doppler
indices.
• UA Doppler index (S/D, PI, or RI) greater than
95th percentile for gestational age is the recommended
threshold for abnormal UA Doppler.

42. • Qualitative interpretation — Absent and
reversed end-diastolic flow velocities (AEDF
and REDF) in the UA are signs of fetoplacental
circulatory deterioration due to increased
vascular impedance to flow and associated
with adverse perinatal outcomes. The
incidence of AEDF or REDF depends on the
risk category of the pregnancy.
Society for Maternal-Fetal Medicine (SMFM). Electronic address: pubs@smfm.org,
Martins JG, Biggio JR, Abuhamad A. Society for Maternal-Fetal Medicine Consult Series
#52: Diagnosis and management of fetal growth restriction: (Replaces Clinical Guideline
Number 3, April 2012). Am J Obstet Gynecol 2020; 223:B2.

43. B. Intrapartum Fetal
Surveillance placenta physiology
• Maternal blood flows through the uterine
arteries into the intervillous spaces then return
through uterine veins to maternal circulation
• Fetal blood flows through the umbilical arteries
into the villous capillaries and returns to the fetus
through the umbilical vein to fetal circulation.
• Exchange of blood gases depends on an
unobstructed blood flow through the placenta

44. Pathophysiology of FHR monitoring
A. In situation of normoxemia, the peripheral
baroreceptors of the near term fetus are
responsible for the control of the arterial
pressure with both systems in action: the
permanent accelerating sympathetic system
and the intermittent braking -
parasympathetic system, which causes short-
term variability.

45. B. In situation of acute hypoxemia, the peripheral
chemoreceptors are stimulated and induce a rapid vagal
mediated fall in heart rate (i.e. deceleration), and a
peripheral vasoconstriction mediated by sympathetic
nervous system.
C. In situation of acidosis, the central chemoreceptor is
activated. It then stimulates the sympathetic system
generating a fetal tachycardia, and inhibits the functioning
of the peripheral baroreceptors, producing minimal to
absent variability.
D. From that comes out that the variability and the heart
baseline are the only two patterns that reflect the fetal
prognosis.
Young P, Hamilton R, Hodgett S, Moss M, Rigby C, et al. (2001) Reducing
risk by improving standards of intrapartum fetal care. J R Soc Med 94(5):
226-231

46. Indications for Electronic Fetal
Monitoring
• Previous history of stillbirth
• Complications of pregnancy
• Induction of Labor
• Preterm labor
• Nonreassuring fetal status; fetal movement
• Meconium staining of amniotic fluid
• Posterm, diabetes, abnormal amniotic fluid

47. Advantages of EFM
• Constant sound of FHR is reassuring and
comforting to the family
• Supplies more data about the fetus and
gradual trends in FHR are more apparent
• Coach uses strip pattern tracing to assist with
support

48. Disadvantages of EFM
• Reduces patient’s mobility
• Requires repositioning of equipment with
fetal or maternal movement
• Can impart a technical air to the birth process

49. Methods of Fetal Monitoring
• Intermittent ausculation by doppler
• Continuous external monitoring
• Continuous internal monitoring

50. External Monitoring
The ultrasound device is
placed over the area of the
fetal back. This device
transmits information about
the FHR
The tocodynamometer
(“toco”) is placed over the
uterine fundus. The toco
provides information that can
be used to monitor uterine
contractions.
Information from both the toco and the ultrasound device is transmitted to the
electronic fetal monitor.
The FHR is displayed in a digital display (as a blinking light), on the special
monitor paper, and audibly (by adjusting a button on the monitor). The uterine
contractions are displayed on the special monitor paper as well.

51. BASELINE RATE
The baseline rate is the average heart
rate of a fetus in a 10 minute window
Ignore any accelerations and
decelerations
Normal =110-160
Reported as a single number, not a
range

54. Causes of tachycardia
Causes
maternal fever
fetal anemia
 drugs
 maternal anxiety
 maternal hemorrhage
Elevated catecholamines

56. Causes of bradycardia
• Maternal beta blocker therapy
• Hypothyroidism
• Hypothermia
• Hypoglycemia
Causes

57. BASELINE FHR VARIABILITY
 Baseline variability refers to the variation of the
fetal heart rate from one beat to the next
• Variability is quantitated as amplitude of peak to
trough in beats/min
• Absent : Undetectable
• Minimal : > Undetectable but < 5 beats/min
• Moderate : 6-25 beats/min
• Marked : > 25 beats/min

58. • Variation of successive beats in the FHR BTBV is
controlled primarily
by the autonomic nervous system.
• ↑ in FHR is due to activation of the sympathetic
nervous system.
• The ↓ in the FHR is due to the activation of the
parasympathetic nervous system.
• The constant push and pull of the sympathetic and
parasympathetic systems creates the BTBV, which
indicates intact fetal CNS.
• At < 28 weeks gestational age, the fetus is
neurologically immature;
thus, ↓ variability is expected.

59. Absent
Minimal
Moderate
Marked
Sinusoidal

60. DECREASES IN VARIABILITY
Prematurity
Fetal hypoxia and acidosis
Fetal sleep states (can last up to 40
minutes)
Congenital heart anomalies
Drugs
– opiates
– anticholinergics / parasympatholytics
– corticosteriods
– MgSO4

61. ACCELERATION
• Increases in the fetal heart rate of 15 bpm, lasting for 15
second or more . Its presence is reassuring.
• Accelerations are associated with fetal movement or
stimulation are often used as a measure of fetal well-
being.
• Absence of accelerations does not necessarily indicate
fetal compromise, but does indicate the need for further
evaluation.
• Their disappearance may signal fetal hypoxia, especially
with other indicators of compromise, such as worsening
variable decelerations, decreased baseline variability,
baseline tachycardia or bradycardia.

63. DECELERATIONS
Decelerations are an abrupt decrease in baseline heart rate
of >15bpm for more than 15 secs
Three kinds
Early Decelerations
Variable Decelerations
Late Decelerations

64. Early Decelerations
 Early decelerations begins at the onset of the
contraction and resolves at the end of the
contraction
 They are associated with head compression
during contractions
 Shape is uniform, symmetrical
 Considered benign with usually no intervention
needed.

66. Variable Decelerations
 Occurs at any time during or between the contraction
 They are associated with cord compression
 They are most often seen in patients with reduced
amniotic fluid
 a visually apparent abrupt decrease in FHR (<30 sec)
 Often drops below 100 bpm
 Shape may be U, V, or W
 Return to baseline varies; may have rapid or
prolonged return to baseline
 Severe uncorrected variables are associated with
fetal hypoxia, acidosis, and low apgars

68. LATE DECELERATIONS
Late decelerations begin at the peak of uterine
contractionand recover after the contraction
ends
 They are associated with uteroplacental
insufficiency
Can be caused by: Pre eclampsia
Placenta abruptio
Uterine hyper stimulation
Intervention usually needed (get baby out)

71. Prolonged Decelerations
Lasts for more than 2 minutes but less
than 10 minutes
 Can be abrupt or gradual
Usually >15 bpm below baseline
Causes include:
• Uterine hyperactivity.
• Maternal hypotension leading to
transient fetal hypoxia
• Umbilical cord compression.

73. SINUSOIDAL PATTERN
• This type of pattern is rare however if
present it is very serious
• Described as a smooth, wave like
baseline, absent beat to beat variability
• This pattern is associated with severe
fetal anemia, severe fetal hypoxia,
fetal/maternal hemorrhage

75. CATEGORY I PATTERN: NORMAL
Definition — A category I pattern is defined
by ALL of this:
●Baseline rate: 110 to 160 beats per
minute (beats per minute [bpm])
●Moderate baseline fetal heart rate
(FHR) variability (amplitude 6 to 25
bpm)
●No late or variable decelerations
●Early decelerations may be present or
absent
●Accelerations may be present or
absent

76. CATEGORY III PATTERN
Definition — A category III pattern is defined by
EITHER of the following criteria:
●Absent baseline fetal heart rate (FHR)
variability and (any of the following):
•Recurrent late decelerations
•Recurrent variable decelerations
•Bradycardia
Late decelerations and variable decelerations are
considered recurrent when they occur with at
least 50 percent of uterine contractions in a 20-
minute window

77. CATEGORY II PATTERN:
INDETERMINATE
The fetal heart rate tracing shows the following:
 Tachycardia
 minimal or marked baseline variability
 absent variability without recurrent
decelerations
 absence of accelerations without absent
variability
 recurrent late or variable decelerations without
absent variability
 prolonged decelerations
The fetus may not be acidotic

78. MANAGEMENT
• Stop oxytocin and prostaglandins.
• Change maternal position and postion her in left lateral
position
• Administer IV fluids.
• If mother is hypotensive, administer vasopressors.
• Administer maternal O2.
• Sterile vaginal exam to exclude cord prolapse, sudden
cervical dilation, or fetal descent
• Prompt delivery if the fetal heart tracing remain non
reassuring

79. Management of category 2 AND 3
• Category II & III Patterns:
• Change maternal position—preferably, to a
lateral position
• Fluid bolus: Administer 500–1,000 mL lactated
Ringer’s solution IV over 20 min
• Maternal oxygen: Administer 10 L/min of O2 by
non rebreather face mask for at least 15 min
• Decrease or stop infusion of oxytocin
• Discontinue cervical ripening agent

80. REFERENCES
1. Goetzl L. Adverse pregnancy outcomes after abnormal first-trimester screening
for aneuploidy. Clin Lab Med 2010; 30:613.
2. Gillieson M, Dunlap H, Nair R, Pilon M. Placental site, parity, and date of
quickening. Obstet Gynecol 1984; 64:44.
3. Pillai M, James D. The development of fetal heart rate patterns during normal
pregnancy. Obstet Gynecol 1990; 76:812.
4. Brown R, Patrick J. The nonstress test: how long is enough? Am J Obstet Gynecol
1981; 141:646.
5. Robert K. Creasy, MD; Creasy and Resnik’s, maternal-fetal medicine principles
and practice, seventh edition
6. Young P, Hamilton R, Hodgett S, Moss M, Rigby C, et al. (2001) Reducing risk by
improving standards of intrapartum fetal care. J R Soc Med 94(5): 226-231
7. Antepartum Fetal Surveillance: ACOG Practice Bulletin, Number 229. Obstet
Gynecol 2021; 137:e116.
8. Indication for outpatient Antenatal Fetal surveillance: ACOG comitee option,
number 828. Obst Gynecol 2021;137:e177