Presentation Obstetrics-Intrapartum fet surveillance

Intrapartum Fetal Surveillance

1. INTRAPARTUM
FETAL
SURVEILLANC
E
Dr.Bila Mary Thomas

2. GOAL
▪Identification of decreased fetal oxygenation
▪Timely and effective intervention
▪Prevention of brain injury

3. METHODS OF FETAL
MONITORING
A. Clinical C.Biochemical
1)Intermittent Auscultation 1) Fetal scalp blood sampling
-Pinard fetoscope
-Stethoscope
-Handheld Doppler device
B.Biophysical
1) External F.H.R Monitoring
2) Indirect F.H.R Monitoring
3) Fetal Electrocardiography
4) Scalp stimulation
5) Vibroacoustic stimulation

4. INTERMITTENT
AUSCULTATION
▪In uncomplicated pregnancies.
▪Doppler better than stethoscope.
▪FHR recorded every 30 minutes interval initially followed by
15 min intervals in the first stage and at about 5 min intervals
in the second stage.
▪The auscultation should made for 60sec particularly before
and immediately following a uterine contraction.

5. FETAL CONDITION
▪Monitor and assess fetal condition
1)Fetal heart rate
2)Liquor
3)Moulding the fetal skull bones

7. CAUSES OF FETAL
TACHYCARDIA AND
BRADYCARDIA
Causes of Fetal Tachycardia Causes of Fetal Bradycardia
•Drugs to mother: •Fetal hypoxia, acidosis
i) beta –sympathomimetic agents used to inhibit •Fetal sepsis, anomalies
preterm labor(isoxsuprine, ritodrine); •Local anesthetic drugs
ii) vagolytic:atropine •Fetal heart condition defect(SLE)
•Maternal:Hyperthyroidism, metabolic acidemia • Maternal:Hypoglycemia,hypothermia
•Infection-both maternal and fetal •Drugs to mother:eg.Pethidine,
•Anemia-both maternal and fetal Methyldopa, Propanolol, MgSO4
•Fetal hypoxia

8. INTERNAL FHR
MONITORING▪Spiral electrode attached 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.
Advantages
▪It can be used in active labor when maternal
movemnts may make it difficult to use an external
monitor.
▪It can be used in obese women.
▪The fetal heart rate monitoring is more accurate.

9. CONTINUOUS ELECTRONIC
FETAL MONITORING
Consist of
•External monitor:An ultrasound transducer
that detects fetal heart rate
•External tocotransducer:A pressure
sensitive device that demonstrates the
beginning and end of contraction and
shows relationship between contractions
and fetal heart accelerations/decelerations.

10. INDICATIONS
A.Maternal conditions:Hypertension, previous cesarean
delivery, induced labor, APH, PROM
B.Fetal conditions:Small fetus(FGR), oligohydraminos,
multiple pregnancy, abnormal FHR on auscultation

11. INTERPRETATION OF FETAL
HEART RATE PATTERN IN
ELECTRONIC FETAL
MONITORINGVarious components include
▪Baseline fetal heart rate
▪Baseline variability
▪Accelerations
▪Decelerations

12. BASELINE FETAL
HEART RATE
▪Mean level of FHR excluding accelerations and
decelerations.
▪Expressed in beats per minute(bpm).
▪Normal baseline FHR is 100-160bpm.
▪Tachycardia:>160bpm.
▪Bradycardia:<110bpm.

13. BASELINE VARIABILITY
▪Oscillation of baseline FHR excluding the accelerations and
decelerations.
▪Variability is the reflex of normal cardiac behaviour in response to
sympathetic and parasymathetic(vagus) has the dominant role in
modulating variability.
▪Baseline variability may be
Absent
Minimal(<5 bpm)
Moderate(6-25bpm)
Marked(>25bpm)

15. CAUSES OF DECREASED
BASELINE VARIABILITY
▪Maternal administration of
•Analgesics
•Sedatives
•Magnesium sulfate
▪Fetal conditions
•Prematurity
•Sleep cycle
•Anemia
•Metabolic acidemia
•Congenital malformations

16. ACCELERATION
▪Transient increase in FHR by 15bpm or more lasting for atleast 15
seconds.
▪Prolonged acceleration lasts>2 min but<10min in duration
▪If an acceleration lasts 10min Or longer, it is baseline change.
▪Acceleration denotes an intact neurohormonal and cardiovascular
activity, therefore healthy fetus.

17. DECELERATION
▪Transient decrease in FHR below the baseline by 15
bpm or more lasting more than or equal to 15
seconds.
▪Three basic types of decelerations observed.
Early deceleration(Type I Dips)
▪Symmetrical gradual decrease and return of the
FHR associated with a uterine contraction.
▪The onset, nadir and recovery of deceleration
coincides with the beginning, peak and ending of
uterine contraction.
▪Caused by head compression( vagal nerve
activation).

18. Late deceleration(Type II Dips)
•Commence after the start of the contraction and return
to the baseline after the contraction is over.
•The nadir of the deceleration occurs after the peak of the
contraction.
•Causes of late decelerations:Placental
pathology(postmaturity, hypertension, diabetes,
placental abruption), Excessive uterine contraction,
injudicious use of oxytocin, Regional anesthesia(spinal
or epidural).

19. Early Deceleration
Late Deceleration

20. Variable Deceleration
1. Declerations are variable in all respect of size, shape, depth, duration
and timing to the uterine contraction.
2. When it is ‘U’ shaped with reduced variability and Or duration more than
or equal to 3 minutes,suggests fetal hypoxia/acidosis.
3. It is thought to indicate cord compression and may disppear with the
change in position of the patient.
4. Accelerations often precede and follow the deceleration called shoulders.
Prolonged Deceleration
1. Decrease from baseline that is 15bpm Or more, lasting>or =2 min
but<10min
2. If lasts 10 min Or longer, it is baseline change
3. Causes:Prolonged cord compression, prolonged uterine hyperstimulation,
severe degree of abruptio, eclamptic seizure

22. 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. Accelerations
are absent.
•Indicates fetal anemia, severe hypoxia/acidosis.

23. THREE-TIERED FETAL HEART
RATE INTERPRETATION SYSTEM
▪Category I:Normal(baseline rate 110-160bpm;FHR
variability-moderate;no late or variable deceleration;early
deceleration present or absent;acceleration present or
absent.
▪Category II:Indeterminate –all tracings not categorized as
category I or III
▪Category III:Abnormal(either absent baseline FHR
variabilitt and any of the following:recurrent late/variable
decelartions, bradycardia or sinusoidal pattern.

25. MANAGEMENT OF NON-
REASSURING FETAL
STATUS(FETAL DISTRESS)
A:Non surgical
▪Lateral positioning avoids compression of vena cava and aorta by the gravid
uterus. This increases cardiac output and uteroplacental position.
▪Oxygen is administered(6-8 L/min) to the mother with mask to improve fetal SaO2
▪Correction of dehydration by IV fluids(crystalloids) improves intravascular
volume and uterine perfusion.
▪Correction of maternal hypotension(following epidural analgesia) with
immediate infusion of 1L of crystalloid(Ringer’s solution).

26. •Stoppage of oxytocin to improve fetal oxygenation. Fetal
hypoxia may be due to strong and sustained uterine
contractions.
•Tocolytic(Inj terbutaline 0.25 mg SC) is given when uterus is
hypertonus and there is nonreassuring FHR.
•Aminoinfusion is the process to increase the intrauterine fluid
volume with warm normal saline(500ml).
•Indications are:
•(a) Oligohydraminos and cord compression(b) To dilute or to
wash out meconium(c) To improve variable or prolonged
decelerations
Advantages:Reduce cord compression, meconium aspiration,
and improves Apgar score. It also reduces cesarean section rate.

27. •If the FHR pattern remains non reassuring, further
tests are performed to rule out metabolic acidosis.
•Tests are(i)To detect FHR acclerations(ii)Scalp
blood pH, (iii) Fetal ECG/ST segment
analysis(STAN)
•If acidosis is excluded-labor is monitored with
repeated testing(every 30 min) to exclude acidosis.
•If the fetus is acidemic –urgent delivery by safest
method(vaginal or abdominal) depending on the
individual case.

28. FETAL SCALP PH
▪In women with ‘abnormal’ fetal heart rate tracings.
▪Done to confirm the presence of fetal hypoxia and
or acidemia.
▪The cervix must be at least 4-5cm dilated and the
vertex at least at -1 station.
▪pH<7.20-fetal acidosis:immediate delivery indicated.
▪pH 7.25-7.2-borderline, repeat in 30min.
▪pH>7.25-Normal, continue monitoring with
electronic fetal monitoring

29. FETAL ELECTROCARDIOGRAM
•Equipment that process Fetal ECG-STAN system
•Fetal hypoxia causes ST segment and T wave changes in the fetal
ECG.
•Fetal ECG analysis(ST-segment analysis) reduces operative
deliver rates compared to CTG alone
FETAL PULSE
OXIMETRY
•Acidosis:O2 sat. <30%for >2min.
•It is no longer used as it’s accuracy is
uncertain.