Assessment of Fetal Maturity and
(A) Antenatal :
fetal movement count.
Chorionic villus biopsy.
of the fetal heart rate.
of the uterine contractions.
advances in intranatal monitoring.
examination in each antenatal visit is the primary and
main assessment of fetal wellbeing. This includes
detection of :
fetal heart sound,
amount of amniotic fluid.
be used for detection of :
age: by measurement of gestational sac, crown rump
length, biparietal diameter or femur length.
the fetus: by fetal heart movement or fetal movement.
Fetal breathing movement. 6-Foetal
Placenta: location , size
depends upon the reflection of the ultrasound waves on
the RBCs inside the blood vessels, so the blood
velocity and flow through these vessels can be
fetal heart rate as early as 10-12 weeks.
of fetal cardiac function.
of blood flow in high risk cases as IUGR, post-term
pregnancy and pregnancy induced hypertension.
DAILY FETAL MOVEMENT COUNT (DFMC)
The test is valid after 30 weeks of pregnancy.
The mother counts the fetal movements she feels in 3
hours during the period of 12 hours e.g. from 9 am
to 9 p.m , one hour at the beginning, one hour at
the middle and one hour at the end of this period.
The count is multiplied by 4 to get the fetal
movements in 12 hours. If it is less than 10
movements, this indicates that the fetus may be at
risk and non-stress test is indicated.
Count-to -ten Cardiff system
The mother counts the fetal movements from 9 am till
she reaches 10 movements. No further count is needed
unless she did not count 10 movements in up to 12
was found that there is a reduction or cessation of
the fetal movement 12-24 hours before stoppage of
the heart " movement
Informative and non-invasive.
Pregnant woman can monitor herself.
Accurate gestational age not required.
the fetal movement is differing from a mother to
fetal movement may occur due to intrauterine sleep.
the fetus occurs if the mother is taking sedatives.
of the fetus may occur without proceeding slowing of
the fetal movement as in abruptio placenta or it may
be preceded by increased flurry movements.
(I) Non-stress Test:
fetal movement( <10/12
hours) or its cessation.
Intrauterine growth retardation especially with a
major cause as pre-eclampsia.
danger as in antepartum hemorrhage.
Biochemical evidence of placental insufficiency.
is done starting from the 30 weeks of pregnancy.
The electronic fetal monitor is used during
pregnancy to record the pattern of fetal heart rate
(FHR) and its response to the fetal movements
reported by the mother by pressing a button in her
The test is carried out for 20 minutes. If fetal
movement did not occur the test is extended for
another 20 minutes during which the fetus is
stimulated mechanically by the 1st pelvic grip or by
acoustic stimulation using an artificial larynx
placed against the maternal abdomen to
" awaken the fetus" .
2 or more fetal movements are accompanied by
acceleration of FHR of 15 beats/ minute for at least
15 secondsí duration. Reactive test means that the
fetus can survive for one week, so the test should
be repeated weekly.
Non -reactive test:
no FHR acceleration in response to fetal movements
so contraction stress test is indicated.
(II) Contraction Stress Test (
Oxytocin Challenge Test):
is done after 32 weeks of pregnancy.
Two transducers are applied to the motherís abdomen;
one to record the FHR pattern and the other to
record the uterine activity.
Three uterine contractions per 10 minutes are
induced by one of the following
IV oxytocin drip starting with 0.5mU/ minute and
doubled gradually or
tactile stimulation of
consistent and persistent late deceleration of FHR,
so placental insufficiency is diagnosed and delivery
by caesarean section is indicated.
late deceleration does not occur with uterine
contractions. It denotes that the fetus can survive
safely for one week when it should be repeated.
Threatened preterm labor.
Rupture of membranes.
Previous classical C.S.
Last for 30 seconds in 30 minutes
Less than 30 seconds in 30 minutes
3 or more discrete body or limb
movements within 30 minutes.
Less than 3 movements.
One or more episodes of limb
extension with return to flexion within 30
Amniotic fluid volume
One or more amniotic fluid pockets
measures 1 cm or larger in 2 perpendicular planes.
Largest pocket measures less than
1 cm in 2 perpendicular planes.
Maximum score 10
Minimum score 0
A score of 8-10
A score of 4-6
deliver if lung is mature otherwise corticosteroids
are given for 48 hours before delivery.
A score of < 4
evaluate for immediate delivery.
AMNIOTIC FLUID STUDY
Procedure of amniocentesis:
(I) Detection of Fetal Maturity:
Lecithin/ sphingomyelin ( L /S) ratio:
34 weeks of gestation, lecithin and sphingomyelin are
present in the amniotic fluid in equal concentrations
( 1/1) . At about 35
weeks , the lecithin
concentration rises so the ratio of L/S is 2/1 or more
with this ratio the risk of respiratory distress is
detection in the amniotic fluid indicates lung maturity.
It is more reliable than L/S ratio as it is not detected
in blood, meconium or vaginal discharge so the
contamination of the sample with any of these does not
confuse the interpretation .
Foam stability (shake) test:
is a rapid test for detection of fetal lung maturity.
test depends upon the ability of the surfactant in the
amniotic fluid, when mixed with 95% ethanol in a glass
tube and shacked well, to generate a ring of foam at
the air-liquid interface that persists for at least 15
fluid creatinine level of 2 mg/ dl or more indicates
fetal kidney maturity providing that maternal serum
creatinine is normal .
Liver maturity :
absence of abnormal haemolysis, it is 0.01 -0.06
OD at 34-36 weeks and continue to decrease up to term.
sebaceous glands of the fetus produce cells containing
lipid so stained orange with Nile blue
sulphate . If 50% or more of
the cells in the amniotic fluid are of these type the
fetus is mature.
(II) Detection of Fetal Abnormalities:
as Downís syndrome (trisomy 21) can be diagnosed by
examination of the desquamated fetal cells in the
Chromosomal study is indicated in the following
women of 35 years old or more as the incidence of
Down's syndrome is increased to reach
1:50 when the mother
is 40 years old or more.
chromosomally abnormal offspring.
abnormality in either parents.
Ultrasonographic markers of chromosomal anomalies as:
cardiac defects , duodenal
atresia, omphalocoele and hands or feet anomalies.
Such markers are present in about 85% of fetuses with
Neural tube defects:
anencephaly and open spina bifida produce increased
level of alpha fetoprotein into the amniotic fluid.
Inborn metabolic errors:
metabolism : e.g.
cystinuria and histidinaemia.
metabolism: e.g. glactossaemia and glucose 6-phosphate
metabolism: e.g. Tay-saachs disease, Niemann-Pick
disease and Gaucherís disease.
Miscellaneous disorders: e.g. congenital adrenal
hyperplasia and congenital nephrotic syndrome.
X- linked recessive disorders:
Duchenne muscular dystrophy and hemophilia.
up of such patients by determination of the bilirubin
level in the amniotic fluid.
(1) Estriol :
Maternal urinary and serum estriol level is an
important index for the integrity of the fetal
adrenal and liver as well as the placenta.
Urinary estriol increases as pregnancy advances to
reach about 35-40 mg/ 24 hours at full term.
Progressive fall in urinary estriol by serial
measurement indicates that the fetus is jeopardous.
Progesterone level can be detected in the serum and
saliva of the pregnant mother and its end product
pregnandiol in 24 hours collection of urine.
is of little practical value in comparison to
urinary estriol detection as the fetus is not
sharing in its synthesis.
(3) Human Placental Lactogen(
Although it was found that hPL falls before fetal
death, it may be within normal range until after
single value of < 4
m g/ ml after
36 weeks is associated with 30% incidence of fetal
(4) Human Chorionic Gonadotrophin (hCG):
no practical value as it can be detected up to few weeks
after fetal death or delivery.
95% of the cells in the smear are of the intermediate
type (navicular cells ) that have folded edges and
present in clusters. About 5% of the cells are of the
In bad pregnancy:
e.g. progesterone deficiency and placental insufficiency
more than 10% of the cells are of the superficial type.
In inevitable abortion:
trophoblastic cells may appear in the smear.
In intrauterine fetal
parabasal cells appear in the smear.
In antepartum rupture of
fetal cells appear in the smear.
At full term:
10% of the cells are of superficial type, clumping and
folding of the intermediate cells become less evident
due to decreasing progesterone level.
Introduced through the
cervix without rupturing the membranes.
It may reveal meconium stained liquor indicating
visualization of the fetus by fibroptic telescope
introduced through the abdominal and uterine walls.
Direct visualization of congenital
- Cranial and
- Neural tube
Fetal blood sampling
for prenatal diagnosis
Fetal skin biopsy
for diagnosis of e.g.
Detailed cytogenetic pattern.
CHORIONIC VILLUS BIOPSY
Transcervical or transabdominal sampling of chorionic
(placental) tissue from the interior of the first
trimester pregnant uterus for prenatal diagnosis of:
Metabolic inborn errors.
Transplacental infections as rubella, toxoplasma and
Injection of water
soluble radiopaque material as urographin into the
amniotic fluid to outline the fetus during X-ray
Injection of oil-soluble radiopaque material as Ethiodol
into the amniotic fluid to outline the fetus as it has a
strong affinity to vernix caseosa giving a clearer view
in X-ray radiography.
Radiological methods are abandoned since the development
of sonography as these have the following hazards:
radiation and radiopaque materials.
obtained data than sonography.
MONITORING OF FETAL HEART RATE
Pinardís stethoscope, or
(B) Electronic Monitoring:
Fetal electrocardiography (ECG):
by external electrodes applied to the motherís
- by an internal electrode applied to the fetal scalp
after rupture of the membranes while the cervix should
be one or more cm dilated.
The electrode is held manually or fixed with clip
or screw. A second electrode lies in contact with
the vagina or cervix.
The signal is transmitted by wire to an amplifier
or paper strip record.
sensitive microphone amplifier is used to amplify the
fetal heart sounds auscultated through the maternal
(III) Doppler ultrasound cardiography:
external transducer applied to the motherís abdomen
is used to detect the blood flow in the umbilical
cord and great vessels .
it is associated with recording of uterine
contractions, it is called cardiotocography (CTG).
Interpretation of FHR:
between uterine contractions.
- Mild: 160-180
Severe: > 180 beats / min.
Mild : 100-120 beats/min.
- Severe: <100 beats/ min.
Loss of beat - to - beat variation:
there is a change of 5-10 beats/ minute every minute in
FHR. Absence of this beat -to - beat variation indicates
Periodic FHR changes:
The pattern with uterine contractions.
Decrease in the FHR with the onset of the uterine
contraction and return to the baseline with the end
of the contraction.
This is usually due to compression of the fetal head
with vagal stimulation.
Decrease in the FHR starts after a lag time from the
onset of contraction and ends after a lag time from
denotes uteroplacental insufficiency.
of different intensity,
pattern, time of onset and offset.
usually denotes cord compression.
MONITRORING OF UTERINE CONTRACTIONS
external transducer is applied to the motherís abdomen
close to the fundus transmitting the strength, frequency
and duration of uterine contractions onto a paper strip
fluid-filled catheter is introduced into the uterus
after rupturing the membranes. The intrauterine pressure
is transmitted to the catheter then to a transducer
giving electrical signals expressing the exact pressure
FETAL BLOOD SAMPLING
Transabdominal passage of a needle into the umbilical
vessels for blood sampling or administration of therapy
which may be hysteroscopic or ultrasonographic guided.
Genetic disorders and karyotyping: replaced by
chorionic villus biopsy.
particularly due to Rh-isoimmunization.
(II) Fetal Scalp Blood Sampling:
rupturing the membrane, a special guarded needle is
introduced through an amnioscope to take a drop of scalp
blood for detection of its pH.
pH of 7.25
or more is normal,
pH of 7.20 or less
in between denotes pre-acidotic range and repeated
estimation is indicated.
RECENT ADVANCES IN INTRANATAL
radiotelemetry of the FHR and uterine contractions
pattern to a 50-100 meters distant monitor.
Computerized data analysis:
Analysis of the various parameters including FHR and
uterine activity. A computerized prognostic comment is
Fetal electroencephalography (EEG).
Continuous fetal tissue pH or PO2
(5) Maternal and
fetal blood lactate measurement.
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see fetal physiology