Ultrasound

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Assessment of Fetal Well-Being
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Ultrasound

• Ultrasound

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Ultrasound

• Definition -- an instrument which uses reflective
  sound waves as they travel in tissue to visualize
  structures in the body

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Purposes of Performing an Ultrasound

• Validate the pregnancy
• Determine how advanced the pregnancy is
• Detect congenital anomalies and problems
• Localize the placenta
• Assess fetal viability heartbeat, breathing
  movements
• Diagnose cardiac problems
• Detect fetal presentation, number of fetus

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Ultrasound

• It is a non-invasive and painless procedure
• Results are immediate
• Allows the mother and family to see the baby

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Ultrasound Nursing Care

• Make sure that the patient has a full bladder
• Place patient on back with a towel roll under one
  hip -- allowing better perfusion of the
  placenta
• The test requires about 20 - 30 minutes

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Alpha - Fetoprotein AFP

• Measurement of a protein produced by the yolk sac
  and fetal liver. Main protein in fetal plasma.
  Diffuses from fetal plasma to fetal urine,
  excreted in amniotic fluid.
• Measured via maternal serum or amniocentesis
• Elevated levels of AFP may be indicative of open
  neural tube defects because the AFP leaks out of
  the fetal circulation into the amniotic fluid and
  chromosome abnormalities.

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Chorionic Villi Sampling
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Chorionic Villi Sampling

• Removal of small tissue specimen from the fetal
  portion of the placenta
• Tissue obtained about 10-12 weeks gestation
• Chromosomal studies performed

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Chorionic Villus Sampling

• Advantage can be done earlier than an
  amniocentesis to detect problems.
• Disadvantage spontaneous abortion

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AMNIOCENTESIS

• Collection of Amniotic Fluid for Testing

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Amniocentesis

• An invasive procedure
• Requires a consent form to be signed
• Performed about 14 - 16 weeks gestation
• Patient must be informed of possible
  complications
• Trauma
• Infection
• Hemorrhage

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Amniocentesis

• Preparation
• Permits signed
• Vital Signs and FHTs
• Abdominal prep and scrub
• Procedure
• Area of insertion is anesthesized and a needle
  inserted into the amniotic cavity and 5 - 30 ml
  of fluid withdrawn for analysis
• Post care / Discharge Teaching
• Vital signs and FHTs normal
• No leakage of fluid from site
• Teach patient to report -- lack of fetal
  movement, discharge or bleeding, abdominal pain,
  or fever

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Amniocentesis

• Why is an Ultrasound performed as part of the
  procedure?
• To detect placement of the placenta

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AmniocentesisTests Performed

• Triple Test
• AFP
• hCG
• Unconjugated estriol
• Genetic studies
• Most commonly used to diagnose Downs
• Fetal Lung Maturity
• L/S ratio lecithin-sphingomyelin ratio

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L/S Ratio Lecithin / Sphingomyelin Ratio

• Lecithin is a major constituent of surfactant.
  As surfactant increases in the lungs, the levels
  of lecithin should also increase.
• Lecithin should become 2 - 3 times greater than
  sphingomyelin by about 35 weeks
• Fetal maturity is attained when the L/S ratio is
  2 1

Assesses Fetal Lung Maturity
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Karotyping and Cell
Enzyme Studies
Determine sex of the fetus
Normalcy of Chromosomes
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Non-Stress Test NST
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Non-Stress TestEvaluation of Fetal Status

• Observation of fetal heart rate associated with
  fetal movement.
• With movement of the fetus, the FHR should
  increase, or accelerate
• This test is based on the knowledge that when the
  fetus has adequate oxygenation and an intact CNS,
  there are accelerations of FHR with movement.

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Procedure for the NST

• Electronic fetal monitor is applied
• As the NST is done, fetal movements are
  documented
• Compare the FHR with the fetal movements
• Results
• Reactive -- two accelerations of 15 BPM lasting
  15 seconds, associated with fetal movement. This
  is an indication of fetal well-being
• Nonreactive -- no accelerations of FHR.
  Indication of need for further assessment

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Non-Stress Test
Example of a reactive non-stress test (NST).
Accelerations of 15 beats per minute lasting 15
seconds with each fetal movement (FM). Top of
strip shows FHR bottom of strip shows uterine
activity tracing. Note that FHR increases (above
the baseline) at least 15 beats and remains at
that rate for at least 15 seconds before
returning to the former baseline.
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Non-Stress Test
Example of a nonreactive NST. There are no
accelerations of FHR with FM. Baseline FHR is 130
beats per minute. The tracing of uterine activity
is on the bottom of the strip.
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NST Management Scheme
If test is non-reactive, woman is re-tested.
If continues to remain non-reactive, will
schedule an OCT.
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Oxytocin Challenge Test OCT
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Contraction Stress Test CSTOxytocin
Challenge Test OCT

• A means of identifying the fetus that is at risk
  for intrauterine asphyxia.
• Usually shows if there is placental insufficiency.

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Procedure for an OCT

• Oxytocin (Pitocin) stimulation started IV
• Electronic fetal monitor attached
• Goal -- have 3 contractions in 10 minutes
• Results
• Negative -- 3 contractions in 10 minutes with NO
  signs of late decelerations
• Positive -- repetitive persistent late
  decelerations occurring with more than half the
  contractions

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Oxytocin Challenge Test
Example of a positive contraction stress test
(CST). Repetitive late decelerations occur with
each contraction. Note that there are no
accelerations of FHR with three fetal movements
(FM). The baseline FHR is 120 beats per minute.
Uterine contractions (bottom half of the strip)
occurred four times in 12 minutes.
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Biophysical Profile
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Biophysical Profile

• Comprehensive assessment of five
• Biophysical variables
• Fetal breathing movement
• Fetal movements of body or limbs
• Fetal tone (extension and flexion of extremities)
• Amniotic fluid volume visualized as pockets
  around the fetus
• Reactive FHR with activitity (reactive NST)

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Biophysical Profile

• By combining these five assessments, the BPP
  helps to identify the compromised fetus and to
  confirm the healthy fetus
• Since it combines several assessments, it is a
  better indicator of fetal well-being

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Biophysical Profile

• A score of 2 is assigned to each normal finding
  for a maximum score of 10.
• Scores of 8-10 are considered normal
• Lower scores are associated with a compromised
  fetus and warrant further assessment and possible
  delivery of the baby.

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Kick Counts

• The mother should assess fetal movements called
  kick counts each day.
• Fetal movement is associated with the condition
  of the fetus.

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The End