Fetal Distress
•The term fetal distress is commonly used to
describe fetal hypoxia during ante partum or
intrapartum period. Which can result in fetal
damage or death if it is not reversed or the
fetus is not promptly delivered.
Signs
Fetal distress can be detected via :-
Abnormal fetal heart ( fetal heart <100/min or >180
beat/ min )
Thick meconium stained amniotic fluid
Abnormal cardiotocography( Non reassuring fetal
status)
-Fetal tachycardia or bradycardiaespecially during & after
contraction
-Decreased beat-beat variability in base line fetal heart
-Late deceleration
Biochemical sign-Fetal scalp blood PH <7.2
or showing elevated lactate
level
Metabolic acidosis is more reliable predictor
of Fetal Distress but is not always available
Cardio-Toco-Graphy (CTG)
•Electronic Fetal Heart rate monitoring in
intra-partum period.
•With stress (contractions, during labour)
•Two probes are used one for FHR &
another at fundus for uterine contractility.
CTG
•One of these sensor records
Uterine Contraction
•The other sensor
(ultrasound sensor)
positioned over fetal heart
beat, uses doppler ultrsound
to detect fetal heart motion .
CTG
•The typical fetal monitor
strip consists of two rows
of graphs;
–Upper graph charting the
fetal heart rate (in beats
per minute) and
–Lower graph charting the
mother's contractions (in
mm of Hg).
CTG
•Strip moves at the
definitive rate of 2-3cm /
minute .
•Each small horizontal
square of graph
represents the span of
10 –15 seconds
(depending upon the
strip progress rate).
. Each small vetical square
is 5 -10 beats
•Test usually lasts for 20
to 40 minutes.
CTG cont.
1.Base line fetal heart rate. (Brady /
Tachycardia)
2.Baseline variability.
3.Acceleration
4.deceleration
•In relation to fetal movement -NST
•uterine contraction -CTG
When is a NST Performed
•NST are generally performed after 28
weeks of gestational age.
•Before 28 weeks, the fetus is not develop
enough to respond to the test protocol.
•Before 28 weeks of gestational age 50%
of NST are non-reactive in neurologically
healthy fetus.
•At 28-32 weeks gestation NST is non-
reactive in 15% cases of healthy fetus
Interpretation
•Normal / Reassuring-
•Suspicious-one non reassuring category
and reminder are reassuring.
•Pathological / Non reassuring-2 or
more non-reassuring categories or one or
more abnormal categories.
Baseline FHR
•Baseline FHR is average fetal heart rate
•noted while the uterus and fetus is at rest
•over a period of two minutes.
•Normal baseline fetal heart rate ranges
between 120 -160 bpm. FIGO
recommends 110 –150bpm.
Baseline variability
•Fluctuations in baseline fetal heart rate.
•Shows an irregular line rather than a
smooth line on monitor strip.
•Normally it ranges from 5 –20bpm.
•Pathological if;
–Absent,
–marked
Accelerations : are increase in FHR by 15bpm or
more lasting for 15 secs. It denotes healthy fetus
•At 32weeks or below acceleration of at
least 10 beats lasting for 10 seconds
should be taken normal instead of 15
beats or more lasting for 15 seconds after
32 weeks of gestational age
Deceleration
•Fall / decrease of fetal heart rate
of > 15 bpm from the baseline
for > 15 second duration.
•Types: three basic types
–Early
–Late
–Variable
Early deceleration
•FHR begins to slow down at
the beginning of uterine
contraction.
•Nadir corresponds to peak
of contraction & FHR
returns to normal before the
contraction passes off.
•Usually not lower than 30-
40 BPM from baseline.
•Occurs due to head
compressionin active
labour.
•No fetal compromise so no
intervention is necessary
Late deceleration
•FHR begins to slow down
after the onset of
contraction,
•nidar of the deceleration
occurs after the apex of the
contraction & FHR returns to
normal after contraction
passes off, but before next
contraction
•Usually not lower than 30-40
BPM from baseline
•Suggestive of utero-
placental insufficiency &
fetal hypoxia
Variable deceleration
•Decreased fetal heart rate.
•Sharp/abrupt in fall & rise. (V U & W pattern)
•sometimes prolonged more than 2minutes.
•No uniform appearance
•May or may not be related to contractions.
2. Placental –Abruptio placentae
-Placental Insufficiency due to any cause
3. Cord -Cord Prolapse
-Cord entaglement tightly around neck
4. Uterus -Uterine hyperstimulation
-Uterine rupture or Scar dehiscence
5. Fetal -Excessive moulding
-Fetal congenital heart lesions
Management of fetal distress
•Attempts to improve the fetal status in utero
•Removal of the fetus from its unfavorable
environment.
Attempts to improve the fetal status in utero
* Correction of maternal distress if present
* Encourage the patient to lie on her side to
remove supine hypotension this increases
cardiac output & utero-placental perfusion.
* Correction of dehydration & acidosis by i.v
fluid crystalloid (RL).
* Rapid blood transfusion in APH
* Rapid i.v fluid (crystalloid) Spinal anaesthesia
hypotension
*Administration of oxygen to mother (6-8 L/min)
*Decrease uterine activity (stop oxytocin drip if used)
* Tocolytic to be given when uterus is hypertonus
* Amnioinfusion –It is a process to increase intra-
uterine fluid volume by introducing
500ml of normal saline in the uterus
in case of thick meconium and
oligohydrmnios
-It dilutes or washout meconium & prevents mecomium
aspiration and cord compression
Removal of the fetus from its unfavorable environment
•If the fetal heart rate pattern remains non
reassuring
•If facilities are available ideal is to perform fetal
scalp blood sample PH → acidosis → immediate
delivery.
•The method of delivery will depend on cervical
dilation, the position and presentation of the fetus
•If fetal distress in 2
nd
stage of labor and
prerequisites of forceps or vacuum are fulfill then
vaginal delivery otherwise C.S.
Meconium Stained Liquor (MSAF/MSL)
•Meconium is thick, dark, green, sticky tar like
substance that is passed as the baby’s first
bowel motion after birth.
•At times meconium can pass before the baby
born (in utero ) & causes discoloring the
amniotic fluid. Liquor look like green, yellow or
brownish in color called MSL
Composition of meconium
-70-80% water
-AF
-Intestinal epithelial cells
-Lanugo etc
Incidence of MSL-About 15-20% of babies are
born with meconium stained
liquor.
-It is rare in premature baby.
Causes of MSL
•Theoretically there are three reasons that a
baby passes meconium in utero:-
1.Baby digestive system has reached maturity and
bowel has begun working.
-It is most common reason in post term baby
-30-40% post term baby have MSAF
2. Cord compression or head compression during
labor→passage of meconium due to same reflex
which causes variable heart rate deceleration.
-This is normal physiological response and can happen
without fetal distress.
3. Fetal distress resulting in hypoxia causes intestinal
ischemia, relaxes the anal sphincter & increases
gastrointestinal peristalsis→passage of meconium.
Grading of meconium stain liquor
MSAF can be
-Light
-Moderate
-Heavy or thick
According to that they are divided in three
Grades.
Grade 1-Meconium Stain Liquor
It is light meconium staining of amniotic fluid
In this liquor is slight greenish or yellowish
tinge
It is usually not related to fetal distress and
usually not causes meconium aspiration
syndrome (MAS)
Grade 2. Meconium Stain Liquor
It is moderate meconium staining of liquor
Liquor look like khaki green or brownish in
color.
It is possible sign of fetal distress but fetal
distress is confirmed if it is associated with
abnormal FHR.
When it is present in early labor can be
more of concern because baby can inhale it
and risk of MAS
Grade 3. Meconium Stain Liquor
Heavy or Thick meconium stain liquor.
Liquor look like pea soup, thick green or black in
color.
Thick meconium is a sign of fetal distress.
In this risk of MAS is very high.
•Fetal distress can be present without meconium
& meconium can be present without FD,
•Light & moderate meconium stain liquor in
absence of other signs of fetal distress is not a
sign of FD.
•Abnormal FHR alone / or abnormal FHR + MSL
is better predictor of FD.
Meconium Aspiration Syndrome (MAS)
Meconium aspiration syndrome is caused by
aspiration of meconium stained liquor by the fetus
in utero or during first breath.
The meconium may block the small air passage
or produce chemical pneumonitis
Diagnosis
Aspiration of meconium from the trachea at birth.
Signs of respiratory distress in neonate.
Chest radiograph shows hyperventilated lung
fields with coarse and patchy infiltrations
( areas of hyperinflation and atelectasis)
D/D early onset or congenital pneumonia
Amnioinfusion-in case of oligohydromnios and
thick meconium stain liquor
Immediate suction of the oropharynx and
endotracheal intubation & suction of larynx prior
to first breath of the neonate is ideal.
Liberal oxygen supply
Antibiotic coverage
Management
Newer Modlities of treatment
•High Frequency Ventilation (HFV)
•Nitric oxide inhalation
•Extracorporeal Membrane Oxygen (ECMO)
Prognosis of MAS →In severe cases perinatal
mortality up to 50%.