1. ASSESSMENT OF FOETAL WELL BEING
ANTEPARTUM AND INTRAPARTUM
DR RAJEEV SOOD ASSOC. PROF. OBG
KAMLA NEHRU HOSPITAL
INDIRA GANDHI MEDICAL COLLEGE SHIMLA

2. INTRODUCTION ANTENATAL FETAL SURVEILLANCE IS
ASSESSMENT OF FETAL WELL BEING IN
ANTEPARTUM PERIOD TO ENSURE
DELIVERY OF HEALTHY NEONATE.
Two main objectives are:-
 Early detection of fetuses at risk to
prevent perinatal mortality and
morbidity.
 Find out normal fetuses and avoid
unwarranted interventions.
2

3. ANTEPARTUM FETAL ASSESSMENT METHODS:-
 1a CLINICAL ASSESSMENT
 Weight gain
 Fundal height
 Abdominal girth
 Auscultation of fetal heart
 1b fetal movement count by mother
 2.ultrasound for fetal parameters
 3.biochemical tests
 4.NST
 5.VAST
 6.CST
3

4.  7.Nipple stimulation test
 8.biophysical profile
 9.doppler
 10.fetal lung maturation test
 11.placental grading
4

5. INDICATIONS
 MATERNAL
 FETAL
 PREGNANCY RELATED
 MATERNAL
 Hypertension
 Diabetes
 Heart disease
 Chronic renal disease
 Sever anemia
 APLA
 Acute illnesses
5

6. Fetal
 Fetal growth restriction
 Rh isoimmunisation
 Fetal cardiac arrythmias
 Fetal infections
6

7. PREGNANCY RELATED Multiple pregnancy
 Gestational hypertension
 Preeclampsia
 Decreased fetal movement
 Abnormal placentation
 Placental abruption
 Amniotic fluid disorders
 PROM
 GDM
 Previous unexplained still birth
 ICP
 Post term pregnancy
7

8. WHEN TO START?
 Depends up on factors like:-
 Past history of adverse outcome
 Severity of maternal and fetal conditions
 Generally Monitoring is recommended when
estimated fetal maturity is sufficient to expect a
reasonable chance of survival should intervention be
necessary.
8

9. CLINICAL ASSESSMENT
 WEIGHT GAIN
9
Recommended Ranges of Weight Gain
During Singleton Gestations Stratified by Pre
pregnancy Body Mass Index
Category BMI Wt. in kgs
Low 19.8 12.5–18
Normal 19.8–26 11.5–12.5
High 26–29 7–11.5
Obese 29 7

10. Symphysio-fundal height
 Measured from superior border of
pubis symphysis to fundus
 From 24th wks of gestation corresponds
to period of gestation .
 Difference of 2- 3 cms acceptable
 below 10th percentile or difference of
>4cms suggests IUGR
 positive predictive value of 60%
negative predictive value of 76.8%
10

11. Abdominal girth
 Measured at lower border of umbilicus.
 Increases by 2.5cm per week after 30wks.
 95-100 cms at term.
 Static or falling values alarming sign.
11

12. Fetal movement count
 Cardiff” count 10” technique
 Daily fetal movement count
 Perception of three movement in 30 minutes.
12

13. Fetal movement count
 Fetus spends 10% of its time making gross fetal
body movements
 Periods of active fetal body movement last about
40 minutes
 Longest period without fetal movements about
75 minutes.
 Mother appreciate 70% to 80% of gross fetal
movements.
13

14.  Fetal movement peak between 9:00 PM and
1:00 AM.
 Time when maternal glucose levels are
falling.
Fetal activity does not increase after meals
or after maternal glucose administration.
14

15. Factors affecting maternal
perception of fetal movement
 Fetal and placental factors :-
 Placental location
 The length and type of fetal movements
 Amniotic fluid volume (AFV)
 Maternal factors :-
 Parity, obesity.
 Psychological factors anxiety.
15

16. ULTRASOUND FOR FETAL
PARAMETERS HIGH RESOLUTION UTRASOUND
REVOLUTIONIZED PRENATAL DIAGNOSIS.
 CAN BE:-
 BASIC
 TARGETED
 BASIC:-(in early pregnancy)
 Done at 10-14wks and includes :-
 No. of fetuses
 Fetal life
 Placental localization
 Internal os diameter
 Cervical length
16

17.  Gestational age
 maternal pelvic masses
 Any gross anomaly like anencephaly,limb
reduction defects.
 Nuchal translucency(80% fetuses with 5%
false positive rates)
 Only in high risk patients
17

18.  CRL smaller than gestational age
chromalsomal anomalies
Absencence of nasal bone at 10-12wks
Down syndrome
NB+NT detection rate of 92% & false positive
rate of 3.5%
18

19. 2nd &3rd triemester
 Serial measurements of BPD,AC,HC,FL.
 HC/AC ratio exceeds 1 before 32wks.
 1 bw 32to 34wks. After 34wk falls below 1.
 In symmetric IUGR remains normal.
 Ratio can identify 85% IUGR fetuses.
 FL/AC remains 22 at all gestational ages from 21wks to term. >23.5
suggest IUGR.
 AC remains single best parameter to detect IUGR with positive
predictive value of 50%.
 Trans cerebellar diameter in mm corresponds to POG from 11wks –
32wks .
19

20. AMNIOTIC FLUID VOLUME
 Single deepest pocket >2cm normal
 Or
 Amniotic fluid index 5-25cm.
20

21. Targetted ultrasound Done in high risk patients
 In developed countries offered to all patients
 Transverse section for fetal head
 Shape and internal structures. BPD,HC Measured to
detect hydrocephalus,anencephaly
 Transverse and longitudinal views of abdomen to
rule out anomalies of stomach, kidneys ,bladder,
ventral wall.
 Transverse section of fetal thorax to four chambered
view of heart.
21

22. Four chambered view of heart
22

23.  Identify three long bones in each limb
and any achondroplasia is looked for.
 Saggittal ,coronal and transverse views taken to rule
out spinabifida.
cephalic index
Biparietal diameter/occipitofrontal diameter
23

24. Fetal ECHO
 Indications
Fetal risk factors
 Suspected cardiac anomaly on level I scan
• Nuchal thickening/lucency
• Diaphragmatic hernia
• Duodenal atresia
• Tracheoesophageal fistula
• Cystic hygroma
 Chromosomal abnormalities
 Twin–twin transfusion
• Acardiac twin
• Vein of Galen aneurysm
24

25.  Maternal risk factors •
 Congenital heart disease
• Exposure to teratogen
 Diabetes
 Maternal infections
Familial risk factors
• Trisomy 21 (Down)
25

26.  Historically optimal timing between 18 and 22 weeks’
gestation.
 moving into an era of early risk assessment .
 fetal echocardiography late first and early second
trimesters
 A limited number of reports describe the utility of
transvaginal imaging between 10 and 13 weeks.
26

27. Non stress test Freeman first described the NST in 1975.
 Physiologic premise of the NST is that:-
Nonhypoxic fetus
stimulus
 accelerate its heart rate
27

28. Method
 FHR and uterine activity are monitored with
an external transducer
 FHR is monitored for 20 minutes.
 For 40 minutes in some cases to compensates
for sleep cycles then called EXTENDED NST.
 In some cases when the fetus is not reactive,
acoustic stimulation by artificial larynx a
sound stimulus for 1 to 2 seconds.
28

29. INTERPRETATION Reactive NST presence of two accelerations of
15bpm over base line for 15sec in a 20-minute
time period with or without fetal movements.
 Nonreactive NST absence of two accelerations
in a 40-minute period with or without acoustic
stimulation over a 40-minute period.
29

30.  NST is not routinely started until 32-weeks
gestation.
 Up to 50% of NSTs reactive from 24- to 28-
weeks gestation.
 85% from 28 to 32 weeks of gestation
 In up to 50% of NSTs variable decelerations
may be observed.
 It last for <30 seconds and <2 during a 20-
minute period
NO fetal compromise
30

31. PREDICTIVE VALUE
 With a reactive NST, the chance for fetal death
within 1 week is 1.9 per 1,000, giving a negative
predictive value of 99.8% after correction for
lethal anomalies.
 Best senstivity and positive predictive value for
IUGR and Hypertensive disorders -70%
 Reactive NST is reassuring.
 Nonreactive NST is nonspecific and requires
further evaluation.
31

32.  The false-positive rate is considerably higher,
ranging from 50% to more than 90% in various
studies.
 In high-risk pregnancies, the false-negative rate
associated with a weekly NST may be
unacceptably high.
 In these cases, increasing frequency of the NST to
twice weekly may be considered.
32

33. VIBROACOUSTIC STIMULATION
TEST
 Used as an adjunct to NST
 If NST non reactive even after 40min then:-
 Continue CTG monitoring till 90min
OR
Perform BPP
OR
VAST
33

34.  Auditory brainstem response functional at 26 to 28
weeks’ gestation.
 VAST increase the incidence of reactive NSTs after 26
weeks’ gestation .
 Reduce the testing time.
 artificial larynx that generates sound 82 Db -100db
with a frequency of 80 Hz.
34

35.  A stimulus for 3 seconds or less is applied
near the fetal head.
 If the NST remains nonreactive
 Stimulus is repeated at 1-minute
intervals up to three times. 35

36.  VAST have shown a decreased incidence of
nonreactive NSTs from 13% to 14% down to 6% to 9%.
36

37. MANAGEMENT PROTOCOL OF NST
NST for 20 min Reactive
Repeate after 1wk Or earlier if situation demands
 If non reactive Extend to 40min
 Non reactive VAST Non reactive
BPP
37

38. BIOPHYSICAL PROFILE
 Thorough evaluation of fetal well-being .
 Potential to significantly reduce the false-positive rate
of the NST/CST.
 The BPP was initially described by Manning and
colleagues .
 Rationale:-Fetal biophysical activities controlled by
centers in the fetal brain sensitive to varying degrees
of hypoxia.
38

39. BPP SCORING( MANNING)
1. Movements Three or more gross body movements SCORE
in a 30-minute period.
 Simultaneous trunk and limb 2
movements count as a single
Movement
 Fewer than 3 gross body movements 0
in a 30-minute period
39

40. SCORE
2. TONE At least one movement of a limb from
a position of flexion to one of extension, 2
with a rapid return to flexion.
 Fetal limb in extension with no return 0
to flexion with movement
 3.Breathing At least 30 seconds of sustained
FBMs observed over a 30-minute period 2
 Fewer than 30 seconds of sustained
FBMs observed over a 30-minute 0
40

41. SCORE
 4.AFPAt least a single amniotic fluid pocket
measuring 2 cm in 2 perpendicular planes 2
 No amniotic fluid pocket that 0
measures at least 2 cm
2 perpendicular planes
 5. NST reactive 2
NST non reactive 0
41

42. Technique
 Performance of an NST.
 For gestations less than 32 weeks, the qualifying
criteria for accelerations are greater than 10 bpm,
lasting at least 10 seconds.
42

43. MANAGEMENT PROTOCOL OF BPP 10 Normal; low risk for chronic asphyxia Repeat testing
at weekly to twice-weekly intervals (IN HIGH RISK CASES)
 8 Normal; low risk for chronic asphyxia Repeat testing
at weekly to twice-weekly intervals If oligohydroamnios
deliver.
 6 Suspect chronic asphyxia If ≥36-37 wk gestation or <36
wk with positive testing for fetal pulmonary maturity, consider
delivery. Otherwise repeat with in 24hrs
 if <36 wk and/or fetal pulmonary maturity testing negative,
repeat biophysical profile in 4 to 6 hr.
 deliver if oligohydramnios is present
43

44.  4 Suspect chronic asphyxia If ≥36 wk gestation,
deliver.
 if <32 wk gestation, repeat with in 24hrs. If repeat
score <6 deliver if >6 observe.
 0-2 Strongly suspect chronic asphyxia Extend
testing time to 120 min.
 if persistent score ≤4, deliver, regardless of
gestational age
44

45.  NST and FBM Has highest senstivity
 Fetal tone has highest specificity
45

46. MODIFIED BPP
 Attempt to simplify and reduce the time.
 Focusing on the components of the BPP most
predictive of perinatal outcome.
 Two parameters:-
 1. NST indicator of present fetal condition.
 2. AFI /AFP a marker of long-term status.
46

47. Contraction Stress Test
CST/OCT first biophysical technique widely applied
for antepartum fetal surveillance.
Principle
uterine contractions
Reduction in blood flow to the intervillous space.
Inadequate placental respiratory reserve
Recurrent late decelerations in response to hypoxia.
47

48. TECHNIQUE
Fetal heart rate and uterine contraction baseline is
determined.
 Blood pressure is recorded every 5 to 10 minutes to
detect maternal hypotension.
oxytocin started @.5-1 miu /min.
An adequate CST requires uterine contractions of
moderate intensity lasting about 40 to 45 seconds
with a frequency of three in 10 minutes.
48

49. INTERPRETATION
Negative: No late or significant variable
decelerations
Positive: Late decelerations with at least 50% of
contractions
Suspicious: Intermittent late or variable
decelerations
Hyperstimulation: Decelerations with
contractions longer than 90 seconds’ duration or
2-minute frequency
Unsatisfactory: Fewer than three contractions per
10 minutes or an uninterpretable tracing
49

50. PREDICTIVE VALUE OF CST
 A negative CST good fetal outcome.
 incidence of perinatal death within 1 week of a
negative CST (i.e., the false-negative rate) to be
less than 1 per 1000.
50

51. MANAGEMENT PROTOCOL OF CST
 Positive CST is usually repeated in 24 hours .
This is of historical importance .
Not used now.

52. CONTRAINDICATIONS
 Placenta previa
 Previous CS
 Multiple gestation
 Polyhydroamnios
 History of preterm
 Incompetent cervix
52

53. Nipple stimulation test
 Alternative method of performing CST
 ACOG Recommends stimulation through light
clothing for two minutes at a time with rest
interval of five minutes.
 Adequate uterine contractions obtained with in
four minutes of stimulation.
53

54. DOPPLER VELOCIMETRY
 Noninvasive technique to assess blood flow by
characterizing downstream impedance
 Three fetal and one maternal vascular circuits :-
Umbilical artery,
 Middle cerebral artery
 Ductus venosus
 Uterine artery
54

55. INDICATIONS
 IUGR
 PIH
 GDM
 RH ISOIMMUNISATION
 INTRAHEPATIC CHOLISTASIS OF PREGNANCY
55

56. UTERINE ARTERY
 INDICATIONS
(1) history of Preeclampsia
 (2) previous child with IUGR
 (3) unexplained high maternal
 serum alpha-fetoprotein level
 (4) high human chorionic gonadotropin
 level.
 (5) thrombophilias
56

57. The indices used to
quantify uterine artery
 systolic (S) to diastolic (D) velocity ratio (S/D)
 pulsatility index (PI)
 resistive index (RI)
 early diastolic notching.
 Abnormalities in these indices are defined as PI or RI
above a chosen value and/or percentile
 the presence of unilateral or bilateral diastolic notches
57

58. How to calculate indices S/D ratio
systolic peak velocity/diastolic peak velocity
 Resistance index (RI)
systolic- end diastolic peak velocity/systolic peak
velocity
Pulsatility index (PI)
systolic-end diastolic peak velocity/time averaged
maximum −velocity
58

59.  Uterine Doppler screening is commonly performed
around 20 weeks.
 increased uterine artery impedance to flow at 20–
24 weeks follow-up at 26–28 weeks.
 Cut-off values at 23 weeks' gestation are:-
 a mean PI above 1.5–1.61.
 mean RI above 0.57–0.58.
 Bilateral notches are found in about 25–30% of
pregnancies at 12 weeks.
 10–15% at 20 weeks .
 5% at 24 weeks.

60.  sensitivity is up to 85% when performed between
22 and 23 weeks’ gestation.
 high risk patients given low-dose aspirin because
of bilateral uterine artery notching at 12 to 14 weeks
have an 80% reduction of placental disease
60

61.  An early diastolic notch in the uterine arteries at
12 to 14 weeks suggest delayed trophoblast
invasion.
 Persistence “notching” beyond 24 weeks
 confirmatory evidence.
61

62. 62

63.  sensitivities and specificities of uterine artery Doppler
in low-risk populations varied from 34% to 76% and
83% to 93%, respectively.
63

64.  For both preeclampsia and IUGR uterine
artery Doppler more accurate in the second
than the first trimester.
 Increased PI with notching in the second
trimester best predictor of preeclampsia.
64

65. 65

66. Wave forms at 16,20,24,28,32,36
wks
66

67. Reverse end diastolic flow
67

68. FACTS SHEET RI had the best discriminatory
ability when compared with the S/D ratio (P<.05),
the PI (P<.001).
S/D ratio, however, remains the most popular
index.
 S/D ratio less than or equal to 3.0.
 Resistance index less than or equal
to 0.6 is considered normal after 27 completed
weeks of pregnancy.
 Benefits of this technique before 28 weeks of
gestation are uncertain.
68

69.  Diagnostic feature of umbilical artery Doppler
waveform is the end diastolic flow.
 Absent or reverse end diastolic flow ominous
finding.
 frequency of absent end diastolic flow is
approximately 2% in high-risk pregnancies .
 0.3% in a general obstetric population.
 In pregnancies complicated with FGR, fetal
surveillance should consist of weekly umbilical
Doppler.
.
69

70.  BPP or NST should be used either as a backup
test or simultaneously with the umbilical
artery Doppler.
 Umbilical Doppler index is high or increasing
 weekly umbilical Doppler ultrasound
+
 Twice wkly NST/ BPP
70

71. MANAGEMENT WITH ABSENT END DIASTOLIC FLOW
 Guided by the gestational age.
 >34 completed weeks Delivery
 Bw 28 to 34 completed conservative
 Daily umbilical artery Doppler, NST, and BPP (or modified
BPP)+ Ductus venosus
 Reverse flow at any gestational age beyond 28 weeks
Delivery
71

72. MIDDLE CEREBRAL ARTERY
 Two major applications
 Monitoring of IUGR fetuses
 Evaluate peak systolic flow in fetuses at risk for
anaemia.
72

73. MCA in Fetal Growth Restriction
 Hypoxia-induced cerebrovascular dilation
 Impedance decreases
 Increases end-diastolic blood flow
73

74.  Contrast to fetuses with normal growth
 Resistance of the MCA is usually higher than in
the umbilical artery.
 MCA Doppler useful to monitor the third-
trimester growth restricted Fetus.
 Redistribution may occur in the presence of
normal umbilical Doppler.
 RI and PI on MCA Doppler in IUGR fetuses
74

75. TECHNIQUE
 Measured at internal third of the vessel
 50 to 100 waveforms in at least 3 sets examined.
Impedance to flow decreases and maximum blood
velocity increases with advancing gestation.
75

76.  MCA-PSV new development.
 better parameter in the prediction of perinatal
mortality than PI/RI.
 MCA PI in IUGR fetuses can normalize in later stages.
 MCA-PSV becomes abnormal, remains as such.
 Ratio of MCA PI to Umbilical PI >1.5
in normal fetal circulatory condition.
76

77. u
77

78. MCA DOPPLER IN FETAL ANEMIA
 RH isoimmunization
 Parvovirusinfection
 fetomaternal haemorrhage
78

79.  Anemic fetus increased cardiac output
 Associated with lower blood viscosity.
 So increased blood velocities
 Peak velocity in the fetal MCA
 value of greater than 1.5(MoMs) for the corresponding
GA
79

80. 80

81.  MCA-PSV for the prediction of severe,
moderate, and mild anemia at a
sensitivity of 100% showed false-positive
rates of 6%, 37%, and 70%, respectively
 Measurements can be obtained reliably
as early as 18 weeks’ gestation.
 Repeated every 1 to 2 weeks depending
on the trend.
 Values after 35wks higher rate of false-
positive results
81

82. Ductus Venosus
 Connects the intra-abdominal portion of the umbilical
vein with the inferior vena cava at its inlet to the right
atrium.
 Shunt plays a critical role in the delivery of well-
oxygenated blood to the left side of fetal heart.
 Sample siteInlet, where the highest velocities are
recorded
 waveform of the ductus venosus triphasic.
82

83. Ductus venosus waveforms
83

84.  Blood flow in the ductus venosus is usually
forward in physiological conditions.
 In the 11–14 weeks, a negative a-wave may be
recorded in about 3% of normal fetuses.
 Absolute blood flow velocities increase,
whereas the pulsatility decreases with
advancing gestation.
 This reflecs decreasing cardiac afterload and
maturation of diastolic ventricular function.
84

85.  IUGR <32 progressive increase in ductus venosus
pulsatility paralleled by decrease of short time
variation of the fetal heart rate pattern.
 Parameters normal in late-onset growth restriction.
 Primary value in early-onset FGR.
 Perinatal mortality increases to 38.8% when venous
Doppler indices become abnormal.
85

86. Management goals & protocol Prevention of stillbirth
 Delivery based on an accurate assessment of fetal versus
neonatal risks.
 Abnormal venous Doppler indices, mandate higher
testing frequency, up to daily testing.
 Reversal of DV a wave increases the risk for an abnormal
biophysical profile score within 1 to 8 days.
 Reversal of DV a wave only becomes an independent risk
factor for neonatal morbidity and mortality after 27
weeks’ gestation.
86

87. Tests for fetal lungs maturity
 1. L/S ratio(>2)
 2.Shake or bubble test
 3.foam stability index
 4.phosphatidyl glycerol
 5.amniotic fluid optical density.
 6.lamellar body count (>30000/micl
 7.amniotic fluid turbidity test
 8. Nile blue sulphatase test
87

89. GOAL
 The timely identification and rescue of the fetus at
risk of neonatal and long term morbidity from
intrapartum hypoxic insult

90. Intrapartum monitoring
 FHR monitoring –
 Intermittent auscultation(IA)
 Electronic fetal monitoring(EFM)
 Fetal Scalp pH
 Fetal Pulse oximetry
 Fetal scalp lactate testing
 ST waveform analysis

91. FETAL HEART RATE MONITORING
 External FHR monitoring-
Hand-held Doppler ultrasound probe
External transducer

92. TECHNICAL CONSIDERATIONS
 Basis for FHR monitoring is beat to beat recording
 For practical purposes ,this is possible only when
direct fetal electrocardiograms are recorded with a
scalp electrode.

93. Internal FHR monitoring-
Spiral electrode attatched to the fetal scalp with a
connection to FHR monitor.
The fetal membranes must be ruptured, and the cervix
must be at least partially dilated before the electrode
may be placed on the fetal scalp.

94. Intermittent auscultation
 In uncomplicated pregnancies .
 Doppler better than stethoscope.
 Every 15 - 30 minutes in active phase of first stage and every 5
minutes in second stage
 Listen in the absence of active pushing and toward the end of the
contraction and at least for 30seconds after each contraction
CONTINUOUS EFM
 No benefit in low risk
 Continuous EFM -when risk factors for present
 Every 15 minutes in first stage and every 5 minutes during the
second stage.

95. Fetal Assessment : IA & EFM
Surveillence
Acceptable methods
Low-Risk
Pregnancies
High-Risk
Pregnancies
Intermittent Auscultation* Yes Yes (a)
Continuous Electronic Fetal
Monitoring (EFM)
Yes Yes (b)
Evaluation Intervals
First-stage Labour 30 min 15 min (a,b)
Second –stage labour 15 min 5 min (a,c)
•a- before, during and especially after a contraction for 60 sec
•b- includes evaluation in every 15 min
• c- evaluation in every 5 min

96. INDICATIONS FOR CONTINUOUS
EFM
Antepartum risk factors-
 Abnormal Doppler umbilical artery velocimetry
 Suspected IUGR
 APH
 HTN / preeclampsia (current pregnancy)
 DM
 Multiple pregnancy
 Uterine scar / previous CS
 Iso-immunisation
 Oligohydramnios / polyhydramnios
 Maternal medical conditions(including severe anaemia, cardiac
disease, hyperthyroidism, vascular disease, renal disease)

97. Risk factors during labour-
 Prolonged rupture of membranes (> 24 hours)
 Meconium-stained or blood-stained liquor
 Fetal bradycardia
 Fetal tachycardia
 Maternal pyrexia > 38 ˚C
 Chorioamnionitis
 Vaginal bleeding in labour
• Prolonged second stage of labour .

98. Other indications
 Any use of oxytocin whether for induction or for
augmentation of labour
 Before and for at least 20 minutes after administration
of prostaglandin
 Epidural analgesia (immediately after inserting an
epidural block)

99. Electronic fetal monitoring
 Various components include
-Baseline
-Variability
-Accelerations
-Decelerations

100. External fetal monitoring
BASELINE
The mean FHR rounded to increments of 5 bpm during a 10-
minute segment, excluding:
—Periodic or episodic changes
—Periods of marked FHR variability
—Segments of baseline that differ by more than 25 bpm
 The baseline must be for a minimum of 2 minutes in any
10-minute segment
 Normal : 110–160 bpm
 Tachycardia: > 160 bpm
 Bradycardia: <110 bpm

101. FETAL HEART RATE MONITORING
 Baseline Variability
 Fluctuations in the baseline FHR that are irregular in
amplitude and frequency
 Visually quantitated as the amplitude of peak-to-
trough in bpm.
Absent—amplitude range undetectable
Minimal—0 to5 bpm
Moderate (normal) — 6 to 25 bpm
Marked—> 25 bpm

102.  Short term variability – small changes in fetal beat to
beat intervals under physiological conditions
 Long term variability- certain periodicity in the
direction and size of these changes causes oscillations
of fetal heart rate around mean level

104. moderate variability

105. Factors affecting variability
 Normal variability : 98% fetuses not acidotic
 Decreased variability: Fetal metabolic acidosis , CNS
depressants, fetal sleep cycles, congenital anomalies,
prematurity, fetal tachycardia, preexisting neurologic
abnormality, betamethasone.
 Increased variability (saltatory pattern):Acute hypoxia
or cord compression, eg 2nd Stage

106. ACCELERATION
 A visually apparent abrupt increase in the FHR
 <32 weeks: >10 BPM above baseline for >10 sec
 >32 weeks: >15 BPM above baseline for > 15 sec
 Prolonged acceleration lasts >2 min but <10 min in
duration.
 If an acceleration lasts 10 min or longer, it is a baseline
change

107. Early Deceleration
 Symmetrical gradual decrease and return of the FHR
associated with a uterine contraction
 The nadir of the deceleration occurs at the same time
as the peak of the contraction.
 In most cases the onset, nadir, and recovery of the
deceleration are coincident with the beginning, peak,
and ending of the contraction, respectively

108. Caused by fetal head compression
by uterine cervix
Usually seen between 4 and 6 cm of
dilation

109. Late Deceleration
 Symmetrical gradual decrease and return of the FHR
associated with a uterine contraction
 The deceleration is delayed in timing, with the nadir of
the deceleration occurring after the peak of the
contraction.
 In most cases, the onset, nadir, and recovery of the
deceleration occur after the beginning, peak, and
ending of the contraction, respectively

110. Associated with uteroplacental insufficiency
Causes -Maternal hypotension,postmaturity, DM,HTN

111. Variable Deceleration
 Visually apparent abrupt decrease in FHR
 The decrease in FHR is ≥ 15 bpm , lasting ≥ 15 sec, and
<2 minutes in duration.
 When variable decelerations are associated with
uterine contractions, their onset, depth, and duration
commonly vary with successive uterine contractions.

112. TYPES
 Typical
 Atypical
 Slow return to baseline
 Prolonged secondary rise in baseline
 Loss of variability during deceleration
 Continuation at lower baseline

113. Classification of the severity of
variable deceleration
 MILD-
Deceleration of a duration of <30sec , regardless of
depth
Deceleration not below 80bpm , regardless of
duration
 MODERATE- Deceleration with a level <80bpm
 SEVERE- Deceleration to a level <70bpm for >60sec

114. Prolonged Deceleration
 Decrease from baseline that is 15 bpm or more, lasting
≥ 2 min but <10 min
 If lasts 10 minutes or longer, it is a baseline change
 Causes-prolonged cord compression,prolonged
uterine hyperstimulation,severe degree of
abruptio,eclamptic seizure,following conduction
anaesthesia

115. SINUSOIDAL PATTERN
 Visually apparent, smooth, sine wave-like undulating
pattern in FHR baseline with a cycle frequency of 3–5
per minute which persists for 20 min or more.
 Indicates
severe fetal anemia as occurs in
Rh isoimmunization
Feto maternal hemorrhage
Twin twin transfusion syndrome
severe hypoxia

116. A

117. Three-Tiered Fetal Heart Rate
Interpretation System
Category I- NORMAL acid base status
• Baseline rate: 110–160 bpm
• Moderate Baseline FHR variability
• No Late or variable decelerations
• Early decelerations: 
• Accelerations: +
Category II-INDETERMINATE not categorized as Category I or III.
Category III-ABNORMAL acid base status-Intervention
• Absent baseline FHR variability and any of the following:
—Recurrent late decelerations
—Recurrent variable decelerations
—Bradycardia
• Sinusoidal pattern

119. RCOG CLASSIFICATION
BASELINE VARIABILITY DECELERATIO
N
ACCELERATIO
N
REASSURING 110-160 ≥ 5 bpm None present
NON
REASSURING
100-109
161-180
< 5 for ≥40 min
but <90 min
Early decel;
typical variable;
single prolonged
≤ 3min
ABNORMAL <100
>180
sinusoidal ≥ 10
min
< 5 for ≥90 min Late decel;
atypical variable;
single prolonged >
3min

120.  Ancillary tests that can aid in the management of
Category II or Category III FHR tracings-
Four techniques are available to stimulate the fetus:
1)fetal scalp sampling,
2) Allis clamp scalp stimulation,
3) vibroacoustic stimulation, and
4) digital scalp stimulation

121. Standard interventions for NRFS -
Supplemental oxygen
Discontinuation of any labor stimulating agent
Changing maternal position
Resolution of maternal hypotension-hydration.
P/V to determine umbilical cord prolapse, rapid
cervical dilation, or descent of the fetal head,ARM
Assessment of uterine contraction .
Tocolytics-in tachysystole with associated FHR
changes.
When the FHR tracing includes recurrent variable
decelerations -Amnioinfusion

123. MANAGMENT
Suspicious CTG-
 If inadequate quality-check contact and connections
 If hypercontractility-discontinue oxytocin, consider
tocolytics
 Maternal tachycardia,pyrexia,dehydration, hypotension
 Supine? Epidural? sedation? drugs?
 i/v crystalloid bolus; 10 L/min O2
If persistent → do ancillary tests
Pathological CTG
 FBS if feasible
 If not feasible-expedite delivery (within 30 min)

124. Effects of Medications on FHR
Patterns
Narcotics-
 decreased variability and accelerations
Corticosteroids-
 Decreased variability (with beta-methasone but not dexamethasone)
Magnesium sulfate-
 A significant decrease in short-term variability, clinically insignificant
decrease in FHR inhibits the increase in accelerations with advancing
gestational age
Epidural analgesia-
 decreased variability and accelerations
Terbutaline-
 Increase in baseline FHR

125. FETAL SCALP PH
 In women with "abnormal“ fetal heart rate tracings .
 Cervix needs to be 4-5cm dilated and Vx at -1 st or
below
 pH <7.20 –fetal acidosis: deliver
 pH 7.20-7.25 – borderline, repeat in 30 min or deliver if
rapid fall
 pH > 7.25 – reassuring, repeat if FH abnormality
persists
 Greater utility of scalp pH is in its high negative
predictive value (97–99%).

126.  Contraindications
 Maternal infection (HIV, hepatitis, HSV)
 Fetal bleeding disorders (e.g. haemophilia)
 Prematurity < 34 weeks
 Face presentation

128. FETAL PULSE OXIMETRY
 Acidosis: O2 sat. <30% for >2min
 Approved by FDA for use in fetuses with NRFS in May
2000
 The ACOG currently recommends against its use until
further studies are available to confirm its efficacy and
safety
 Insufficient evidence for its use as an adjunct or
independent of electronic fetal surveillance.

129. FETAL SCALP LACTATE TESTING
 Higher sensitivity and specificity than scalp pH
 > 4.8 mmol/L : acidosis
 Clinical trial that compared the use of scalp pH to
scalp lactate level did not demonstrate a difference in
the rate of acidemia at birth, Apgar scores, or neonatal
intensive care unit admissions
 Not recommended for routine use

130. ST WAVEFORM ANALYSIS
 Method: STAN S31 fetal heart monitor(USFDA)
Scalp electrodes
 The electrical fetal cardiac signal – P wave, QRS
complex, and T wave – is amplified and fed into a
cardiotachometer for heart rate calculation

131.  Restrict fetal ST waveform analysis to those with non
reassuring fetal status on EFM
 The use of ST waveform analysis for the intrapartum
assessment of the compromised fetus is not recommended
for routine use at this time.

132. Thankyou
132