1. By Prof. Unn Hidle Updated Spring 2010
Diagnostic Tests By
Prof. Unn Hidle
Updated Spring 2010

2. ULTRASOUND

3. Ultrasound Description Implementation
Outlines and identifies fetal and maternal structures (uses high frequency sound-waves)
Assists to confirm estimated date of delivery
Implementation
Previously, the test used to be done with a full bladder (drink 6-8 glasses of water pre-test), but with high-tech ultrasound, it is usually no longer necessarry.
Inform the client that the test presents no known risks to client or fetus

5. AMNIOCENTESIS

6. Description
Aspiration of amniotic fluid done from 14 weeks of pregnancy and on
Performed to determine genetic disorders (after AFP), the sex of the fetus, and fetal lung maturity (L/S ratio - this is later in pregnancy)
Risks
Maternal hemorrhage
Infection
Rh isoimmunization
Abruptio placentae
Amniotic fluid emboli

7. Implementation Instruct client to empty bladder before procedure
Prepare client for ultrasound, which is performed to locate the placenta
Obtain baseline vital signs and FHR, and monitor every 15 minutes
Position client supine
Instruct client that if chills, fever, leakage of fluid at the needle insertion site, decreased fetal movement, or uterine contractions occur, to notify the physician or health care provider

9. CHORIONIC VILLUS SAMPLING

10. Chorionic Villus Sampling (CVS)
Description
Aspiration of a small sample of chorionic villus tissue at 8 to 12 weeks' gestation
Test is performed for the purpose of detecting genetic abnormalities
Implementation
Usually, the client is instructed to drink water to fill the bladder before the procedure to aid in the position of the uterus for catheter insertion
Instruct the client to report bleeding, infection, or leakage of fluid at insertion site after procedure
Rh-negative women may be given RhoGAM for risks related to the procedure

11. Chorionic Villi Sampling

12. FETOSCOPY

13. Endo-vaginal ultrasound used to locate area to insert catheter into uterus through the maternal abdomen for skin and blood samples:
Percutaneous umbilical blood sampling (PUBS)
Fetal blood is used to help diagnose conditions such as hemophilia, congenital rubella, toxoplasmosis, etc.

15. COMPUTER AXIAL TOMOGRAPHY
(CAT SCAN or CT SCAN)

16. NUCLEAR MAGNETIC RESONANCE IMAGING
(NMRI)

17. FETAL ECHOCARDIAGRAPHY
(EFM & IFM)

19. NON-STRESS TEST
(NST)

20. Non-stress test Description
Performed to assess placental function and oxygenation
Determines fetal well-being
Evaluates fetal heart rate (FHR) in response to fetal movement

21. Implementation
External ultrasound transducer and the tocodynamometer (toco) are applied to the mother and a tracing of at least 20 minutes’ duration is obtained so that the FHR and the uterine activity can be observed
Obtain baseline blood pressure and monitor BP frequently
Position mother in the left lateral position to avoid vena cava compression (reality: SUPINE!!!!)
Ask mother to press a button every time she feels fetal movement
The monitor records a mark at each point of fetal movement, which is used as a reference point to assess FHR response

22. Interpretation: Reactive Nonstress Test (Normal/Positive)
Indicates a healthy fetus
Two or more fetal heart rate accelerations of at least 15 beats per minute, lasting at least 15 seconds from the beginning of the acceleration to the end in association with fetal movement, during a 20-minute period
Nonreactive Nonstress Test (Abnormal/Negative)
No accelerations or accelerations of less than 15 beats per minute or lasting less than 15 seconds in duration for a 40-minute observation
Unsatisfactory
Cannot be interpreted because of the poor quality of the FHR

24. OXYTOSIN CHALLENGT TEST
(OCT)
(OST)

25. Assesses placental oxygenation and function
Description
Assesses placental oxygenation and function
Determines fetal ability to tolerate labor and determines fetal well-being
Fetus is exposed to the stressor of contractions to assess the adequacy of placental perfusion under simulated labor conditions
Performed if non-stress test is abnormal *** REALITY: VERY RARELY used anymore since it is so risky!

26. Implementation
The external fetal monitor is applied to the mother and a 20 to 30-minute baseline strip is recorded
The uterus is stimulated to contract either by the administration of a dilute dose of oxytocin (Pitocin) or by having the mother use nipple stimulation (very rare!) until 3 palpable contractions with a duration of 40 seconds or more in a 10-minute period have been achieved
Frequent maternal BP readings are done and the client is monitored closely while increasing doses of oxytocin are given

27. Interpretation Negative Contraction Stress Test (Normal)
Represented by no late or variable decelerations of the fetal heart rate
Positive Contraction Stress Test (Abnormal)
Represented by late or variable decelerations with 50% or more of the contractions in the absence of hyperstimulation of the uterus
Equivocal
Contains decelerations, but with less than 50% of the contractions, or the uterine activity shows a hyperstimulated uterus
Unsatisfactory
Adequate uterine contractions cannot be achieved, or the FHR tracing is not of sufficient quality for adequate interpretation

29. FETAL BIOPHYSICAL PROFILE
(FBPP OR BPP)

30. Fetal Biophysical Profile
Overall, evaluates fetal status
Assesses 5 fetal variables:
FHR with activity = reactive NST
Amniotic fluid volume
Fetal tone (flexion and extension of extremities)
Movements of body or limbs
Fetal breathing movements (oxygenation)

31. MATERNAL SERUM STUDIES
MATERNAL SERUM STUDIES *** Some of these will be discussed in details throughout the course
TORCH
ALPHA-FETOPROTEIN (AFP)
ESTRIOL LEVEL
HCG
TRIPEL MARKER SCREENING
QUADRUPLE MARKER SCREEN

32. TORCH
T= Toxoplasmosis
O= Other (HIV, HIB, Variella, parovirus, syphillis, etc)
R= Rubella
C= Cytomegalovirus (CMV)
H= Herpes Virus Type II

33. Alpha-Fetoprotein Screening (AFP)
Description
Assesses the quantity of fetal serum proteins and if elevated is associated with open neural tube and abdominal wall defects
Can detect spina bifida (elevated) and Down’s syndrome (decreased)
Implementation
Explain that the level is determined by a single maternal blood sample drawn at 15 to 18 weeks' gestation
If the level is elevated and the gestation is less than 18 weeks, a second sample is drawn
An ultrasound is performed when the level is elevated to rule out fetal abnormalities or multiple gestation

34. Estriol Level Primary estrogen secreted by the placenta
Measurements are used to assess placental functioning and fetal viability
Not a routine test
28 weeks and Q week thereafter
Low levels = fetoplacental deterioration

35. Triple-Marker Screening
Includes:
Human Chorionic Gonadotropin (HCG)
Unconjugated estriol
MSAFP (Maternal Serum AFP)
Screen for chromosomal abnormalities
Increases detection of Trisomy 18 (Edward’s syndrome) and Trisomy 21 (Down’s syndrome)
Test is positive if:
Decreased Estriol and MSAFP
Increased HCG
Amniocentesis is offered if positive

36. Now, also a Quadruple screen
Fairly new!
Combines the triple screen and a test for the hormone inhibin A, which is produced by the fetus and the placenta
One large study of over 23,000 women has reported that the quadruple screen detects almost 86% of all Down syndrome cases. Based on this study, the quadruple test is more likely to pick up Down syndrome and may be less likely to be false-positive than the triple screen

37. Summary findings:
AFP: Increased = Neural Tube Deformity Decreased = Down’s syndrome
HcG: Increased = Down’s syndrome
Estriol: Decreased = Down’s syndrome
Inhibin A: Increased = Down’s syndrome
All findings, including type and amount of elevated or decreased levels, are evaluated to determine the risk for potential outcomes.

38. Other tests…… Kick Test (Fetal Movement Counting) Description
Mother lies down on the left side for 1 hour after meals and counts fetal kicks for 30 minutes
Instruct client to notify physician or health care provider if there are fewer than 5 kicks in 1 hour

39. THE END!!!!