2. Prenatal Assessments and
screening
Chorionic Villous sampling:
10-12 wk using U/S to aspirate
trophoblastic tissue
Can be done either transabdominally or
transvaginally
Detects chromosome abnormality
Risks: miscarriage, bleeding, infection &
PROM
3. Prenatal Assessments and
screening cont.
Triple or Quad Screen
Blood drawn between 15-20 wks
Can detect Down’s syndrome, other
chromosomal abnormalities and neural
tube defects
Values of blood tests added together to
determine risk
Screening tool – further testing needed for
definitive diagnosis
4. Ultrasound
Developed in WWII with submarines
Diagnostic use since 1950s
Definition: transmission of sound
waves to investigate an object
(Kline-Fath & Bitters, 2007)
5.
6. Placental grading
Grade 0 – smooth, dense w/o
echogenic areas
Grade 1 – undulations present, some
echogenic areas
Grade 2 – deeper and > indentations,
more echogenic areas
Grade 3 – dense echogenic areas w/
indentations, areas of calcification
7.
8. Amniocentesis
Trans-abdominal needle aspiration of
10-20 ml of amniotic fluid for lab
analysis
Done under ultrasound
Requires sterile technique and time out
9. Amniocentesis
Indications:
Genetic
R/O infection
Fetal lung maturity
Assess for bilirubin with hemolytic
incompatibility
10. Amniocentesis
Timing:
Early – performed between 11-14 wks
Significantly higher pregnancy loss
Post procedure fluid loss
2nd trimester – performed between 15-20 wks
Usually for genetic screening
3rd trimester
Usually for fetal lung maturity
(Gilbert, 4th edition, pg 93)
11. Cordocentesis /
Fetal Blood Transfusion
Blood Transfusion for
anemia
How much blood is
given?
Graph is used correlating
the hematocrit of donor
blood to the hematocrit of
the fetus to determine
donor blood volume to be
given
13. Amnioreduction
Reduces amount of amniotic fluid
around fetus
Procedure like amniocentesis only with
tubing to suction canister or stopcock
Done to relieve maternal symptoms or
with twin to twin transfusion syndrome
15. Fetal MRI
Superior soft tissue contrast test
Does not use radiation
Used for fetal brain, spinal deformities,
lesions, masses
Also can assess placental and cord malformations
Also used to measure lung volume
Research still continuing for PPROM pts
(Kline-Fath & Bitters, 2007)
16. Fetal MRI Con’t
Not recommended in first trimester
(no documented studies on harm
from heat or sound, but not recommended)
Not used routinely, only after U/S not able to detect
Contrast dye not recommended
Informed consent
(Kline-Fath & Bitters, 2007)
18. Vibroaccoustic Stimulation (VAS)
Artificial acoustic stimulation
Done after 25 wks gestation when fetus can hear
After 10 minutes of baseline and no
accelerations, place the artificial larynx on the
maternal abdomen over the fetal head
19. Vibroaccoustic Stimulation
Provide 5-10 sec stimulation near fetal
head, wait one minute
If no acceleration repeat cycle for a
total of three times
if non-reactive after 40 minutes,
proceed with further evaluation
20. Vibroaccoustic Stimulation
Fetuses 28 weeks or greater respond
to VAS with a consistent increase in
heart rate.
Observed changes are greater as term
is approached.
22. References
Gilbert, E. S., (2011) 5th edition Manual of High Risk
Pregnancy and Delivery.
Kline-Fath, B. & Bitters, C. (2007) “Prenatal Imaging”
Newborn and Infant Nursing Reviews, Vol.7, No. 4.
Mattson, S. & Smith, J.E., (2011) 4th edition Core
Curriculum for Maternal-Newborn Nursing.
Queenan, J.T., Hobbins, J. C., & Spong, C. Y. (2005)
4th edition, Protocols for High-Risk Pregnancies
Notas del editor
Several sites are utilized in aspiration. Can be done earlier than anmio
Triple screen: maternal serum alpha fetoprotein (MSAFP), beta hCG, uncongigated estriol Quad Screen: above plus pregnancy associated plasma A protein Need to be aware of maternal weight, gestational age, multiple gestation, race and diabetes – all these can skew results
Many studies, none to find side effects to fetus
Done with U/S
For ABO incompatibilities or hydrops, can tell amt of bilirubin in amniotic fluid to see if fetus needs transfusion
Isoimmunization(mom antibodies attack fetal RBC), parvo virus (slows production of RBC), fetal maternal hemorrhage
Graph is little blurry but shows how much blood to transfuse.
Magnetic resonance imaging Able to separate maternal and fetal tissue, clearer image Claustrophobia, size of abd and fitting in chamber
Due to organ formation
Watch language with pt – tazer, buzzer, zapper VAS programmed for this time, push button till stops Decels common Do not use if fetus compromised or has heart issues