Tests Performed During Pregnancy
BIOCHEMICAL TEST (early pregnancy)
HUMAN
CHORIONIC GONADOTROPIN (HCG)
·
Tests for
pregnancy.
·
HCG is
produced by syncytiotrophoblast of placenta and secreted I both mother and
fetus blood.
·
Half-life
of HCG is 36hrs.
·
Radioimmunoassay
method it detected in urine as early as 8-9 days of post fertilization.
·
The
maximum level 100-200IU between 60-70 days of pregnancy.
·
Decrease
level found in: - spontaneous abortion, ectopic pregnancy.
·
Increase
Levels found in: - May indicate multiple pregnancies, hydatidiform mole, Down
syndrome.
·
HCG
disappears from circulation within 2 weeks of delivery.
CHORIONIC
VILLUS SAMPLING
·
It is performed for prenatal
diagnosis of genetic disorder.
·
It is done through
trans-cervical (10-12 weeks) and trans-abdominal from 10weeks to term.
·
Few villi collected from the chorion
frondosum.
·
Earlier testing time than
amniocentesis permits earlier decision regarding termination
·
Also decrease risk of 1st
trimester spontaneous abortion and costs less than amniocentesis but for
confirmation required amniocentesis.
·
Complications: fetal loss (1-2%), limb reduction
defect high are high when CVS was performed at less than 10weeks of gestation.
Nursing role:-
·
Full bladder to serve as
acoustic window.
·
Assess vital signs and absence
of uterine cramping.
·
Provide emotional support.
·
Teach spotting for 3 days is
expected after trans-cervical route.
·
Report flulike symptoms and
vaginal discharge of blood, clots, tissue, or amniotic fluid.
·
Avoid sexual activity, lifting,
or strenuous activity until spotting resolves.
·
Ensure genetic counseling if
appropriate.
MATERNAL SERUM ALPHA-FETOPROTEIN (MS-AFP)
SCREENING
·
Fetal protein used to screen
for neural tube defects and abdominal wall defect.
·
AFP is an oncofetal protein.it
is produced by yolk sac and fetal liver.
·
Test is done between 15-20
weeks.
·
MSAFP level is elevated: a.) wrong gestational age b.) Open neural
tube defects c.) Multiple pregnancy, RH
isoimmunisation d.) IUFD e.) Anterior abdominal wall defects f.)
Renal anomalies.
·
MSAFP Decrease Levels found in: - a.)Down syndrome
b.)Gestational trophoblastic disease.
TRIPLE TEST:-
v Is it a
combined biochemical test which includes MSAFP, HCG, and UE3 .it is used for
detection of Down syndrome?
v It case of Down syndrome MSAFP
AND UE3 level low and HCG level high.
v It is performed at 15-18 weeks.
QUDRUPLE TEST:-
v INHIBIN a glycoprotein .it is produced by corpus luteum and
placenta. Serum level of inhibin A raise
in case of down syndrome
v In quadrat test is combination of four MSAFP, HCG, UE3, inhibin A.
all four level are determined for Down syndrome.
v In Down syndrome MSAFP, UE3 level is low and HCG, inhibin level is
elevated.
ACETYL CHOLINE ESTRASE:-
·
It level is elevated in case of
Down syndrome.
PERCUTANEOUS
UMBILICAL BLOODS SAMPLINGS (Cordocentesis)
·
Fetal cord blood assessed at
18-20 weeks. it involves insertion of
needle directly in to the fetal umbilical vein
under the ultrasound guidance .Identifies some maternal/fetal problems
·
Complications:-abortion, IUD, preterm labor
Nursing
role:-
·
Obtain consent
·
Full bladder may be necessary
·
Assess uterine activity, FHR,
and reactivity for at least 1 hour.
·
Teach to take antibiotics and
temp 2 times daily and report increase temperature.
·
Do USG to find out any type of
bleeding or hematoma after one hour the procedure.
AMNIOCENTESIS
·
It is invasive procedure .it is
performed between 14 and 16 weeks
under ultrasonic guidance (early
amniocentesis done at 12-14 weeks of gestation) .the fetal cells obtained
in this procedure for cytogenetic analysis.
·
It identifies chromosomal disorders (e.g., Down
syndrome, neural tube defects), fetal lung maturity, and metabolic disorder.
·
14–16 weeks: - amniocentesis done along with Ultrasonic guidance to identify fetal parts and pockets of amniotic
fluid.
·
Complications:- Preterm
labor(later in pregnancy), amniotic fluid emboli, infection
Nursing
role:-
·
Obtain consent
·
14–16 weeks :- Bladder must be full to raise
uterus (means before 20 week)
·
Second half of pregnancy:- Empty bladder to
decrease confusion with uterus (means after 20 week)
·
Hip roll to decrease
hypotension.
·
Assess maternal vital signs,
fetal cardiac activity.
·
Mild cramping is common.
·
Fluid leakage is usually
self-limiting.
·
Tell patient to avoid
intercourse, heavy lifting, and strenuous activity for 24hr after test.
·
Report increase temperature,
persistent cramping, or vaginal discharge.
BIOPHYSICAL
TEST (late pregnancy)
BIOPHYSICAL
PROFILE
·
Biophysical profile in early
pregnancy is done (10-14 weeks) to
detect fetal anomalies .CRL smaller then gestational age is associated with
Down syndrome .absence of nasal bone on USG at 10-12 weeks is associated with
Down syndrome.
·
Biophysical profile is done
under ultra-sonographic examination.
·
Biophysical profile in late pregnancy- screening test for
utero-placental insufficiency.
·
Modified biophysical profile Consists NST and determined AFI. it
done in late trimester (2nd and 3rd trimester)
·
Biophysical profile test include in late pregnancy: - 1).fetal movement count 2) NST 3.) CST 4.) Cardiotocography 5.)
Fetal biophysical profile 6.) Doppler ultrasound 7.) Amniotic fluid volume 8.)
vibroacoustic stimulation test
·
Nursing role: Same as ultrasonography; emotional
support
Ultrasonography
·
It is performed for prenatal
diagnosis of genetic disorder.
·
It is done though the trans-cervical (10-12weeks.) and
trans-abdominal in mid and late pregnancy to assess gestation period.
·
Use to assess or diagnose
Bi-parietal diameter (BPD), abdominal circumference (AC), head circumference
(HC), femur length (FL), crown rump length (CRL) and amniotic fluid volume.
·
Fetal nutrition can assess
through the abdominal circumference.
AMNIOTIC FLUID TESTS
·
Tests for amniotic fluid with
ruptured membranes.
·
Nitrazine test: -Positive test tape dark blue or gray/green
·
Fern test:-Fern like pattern under
microscope by the effects of salts of amniotic fluid. It indicates the presence
of amniotic fluid.
·
Using sterile technique, a
specimen is obtained from the external OS of the cervix and vaginal pool and is
examined on a slide under a microscope.
Nursing role: -
·
Dorsal lithotomy position
·
Encourage coughing to increase
fluid expulsion
·
Touch nitrazine tape to vaginal
secretions
·
For fern test, use cotton-tipped applicator
to collect secretions and draw over glass slide.
FETAL FIBRONECTIN TEST
(FFN)
·
Swab of vaginal/cervical
secretions for fetal fibronectin.
·
Test is used if at risk for
preterm labor, before 37 week’s gestation.
·
FFN leaks with amniotic sac
separation.
·
Presence may predict labor
onset
·
A positive result indicates the onset of labor in 1 to 3 week.
Nursing
role:
·
Assist with dorsal recumbent or
lithotomy position
·
Sample collection is obtained
with cotton swab.
NONSTRESS TEST (NST)
·
Test is done to assess the FHR
acceleration with fetal movement (cardiotocography ), when present indicate
healthy fetus.it identified the fetal wellness rather than illness .test done
after 28weeks of pregnancy.
·
Interpretation: - 1. Reactive (reassuring) when two or more acceleration of more than 15 beats per minutes
above the baseline and longer than 15 seconds in duration are present in a 20
minute observation.it means negative test.no need of further test.
·
2. Non-reactive (non-reassuring):-
absence of any fetal activity.it means positive test needs CST.
·
3.Unsatisfactory: - Less than
2 accelerations in 20min; accelerations do not meet reactive criteria;
inadequate quality recording for interpretation
Nursing role: -
·
Left lateral position to
decrease vena cava compression
·
Transducer and toco-dynamometer
to abdomen apply.
·
Teach to press event button
with fetal movement.
·
Observe fetal monitor.
CONTRACTION
STRESS TEST (CST)
·
Test assesses placental
oxygenation and function.
·
Contractions stimulated (using
oxytocin) and fetal response monitored and determines the fetal well-being.
·
Done after nonreactive NST
·
Negative: -
·
Normal baseline FHR, FHR
accelerations with fetal movement, and no late decelerations with 3
contractions in 10min indicates healthy fetus
·
Oxytocin discontinued
·
IV continued until uterine
activity returns to prior status
·
Fetus likely to survive labor
if it occurs within 1wk with no maternal/fetal change
·
Positive: -
·
Late decelerations with 50% of
contractions indicates fetal compromise; monitor mother/fetus; prepare for
labor induction
·
Suspicious: -
·
Late decelerations with less
than half the contractions
Nursing
role: -
·
Obtain consent
·
semi-Fowler’s with lateral tilt
·
Doppler transducer to abdomen
·
30min baseline maternal vital
signs and FHR
·
Assist with stimulation
·
Monitor IV and mother for signs
and symptoms of preterm labor
FETAL
MOVEMENT COUNT: - (kick counts)
·
The client sits quietly or lies
down on her side and count fetal kicks are instructed.
·
Fetal movement count done by
any of the two method:-
·
Cardiff’ counts 10’formula:-the patient
counts fetal movement starting at 9 am. And counting end when 10 movements
perceived.
·
She is instructed to report physician -1.less than 10 movements
occurs during 12 hours on 2 successive days or 2.no movement is perceived even
after 12 hrs. In a single day.
·
Daily fetal movement count (DFMC):-
there counts each of one hour’s duration (morning, noon and evening) are
recommended. The total counts multiplied by four gives daily (12hrs.) FMC.
·
If there is no. of kicks less
than 10 in 12 hours. (Or less than 3 in each hour.)
·
After 28 weeks fetal movement
counted by patient at same time daily
·
Less FMC indicate fetal
compromise.
·
Nursing management:-
·
Teach pt. to assume a
comfortable position
·
Hands on abdomen
·
Count movements for 1hr.
DOPPLER
STUDIES (UMBILICAL VESSEL VELOCIMETRY)
·
Measures blood flow velocity
and direction in uterine/fetal structures
·
Decrease Umbilical vessel flow
seen in IUGR, preeclampsia, eclampsia, and post term.
BIOCHEMICAL
TEST IN LATE PREGNANCY
·
In late pregnancy biochemical test done for assessment of pulmonary
maturity.
·
Pulmonary maturity confirmation
reduces the RDS in newborn.
·
RDS is caused by deficiency of
pulmonary surfactant which is synthesized by type 2 alveolar cells.
·
Estimation of pulmonary
surfactant by L:S
(lecithin/sphingomyelin)
·
L: S ratio at 31-32 weeks – 1,
at 35 weeks -2 and L/S ration > 2 indicate pulmonary maturation.
·
Shake test or bubble test.