12. Lab Testing and Antepartal Fetal Surveillance Flashcards Preview

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Flashcards in 12. Lab Testing and Antepartal Fetal Surveillance Deck (83):
1

Purpose of test: Blood Grouping

To determine blood type and Rh

2

Purpose of test: Hemoglobin or Hematocrit

To detect anemia. (Often checked several times during pregnancy)

3

Purpose of test: CBC

Complete Blood Count:

To detect infection, anemia, or cell abnormalities

4

Purpose of test: Rh Factor and Antibody Screen

To screen for possible maternal-fetal blood incompatibility

5

Purpose of test: VDRL or RPR

To screen for syphillis

(Venereal Disease Research Laboratory, Rapid Plasma Reagin)

6

Purpose of test: Rubella Titer

To determine immunity

7

Purpose of test: Tuberculin Skin Test

To screen for tuberculosis

8

Purpose of test: Hemoglobin Electrophoresis

To screen for sickle-cell trait (if client is African-American

9

Purpose of test: Hepatitis B

To detect presence of antigens in Maternal Blood

10

Purpose of test: HIV screen

Voluntary test encouraged to detect HIV antibodies

11

Purpose of test: Urinalysis

To detect renal disease or infection

12

Purpose of test: Papanicolau Test

To screen for cervical neoplasia

13

Purpose of test: Cervical Culture

To detect group B strep and STDs

14

Purpose of test: Triple Screen

To screen for fetal anomalies

15

What three tests comprise a "Triple Screen"

• Maternal serum alpha-fetorotein
• Human Chorionic Gonadotropin
• Estriol

16

Purpose of test: Maternal Blood Glucose

To screen for gestational diabetes

17

Test Significance / Course of Action: Blood Grouping

Identifies possible causes of incompatibility with the blood of the fetus that may cause jaundice

18

Test Significance / Course of Action: Hemoglobin or Hematocrit

Hgb < 11 g/dL or Hct < 33% may indicate a need for iron supplementation

19

Test Significance / Course of Action: CBC

12,000 mm3 or more white blood cells or decreased platelets require follow-up

20

Test Significance / Course of Action: Rh Factor and antibody screen

If mother is Rh (-) and Father is Rh (+) or antibodies are present, additional testing and treatment are required.

(If mom is negative, RhoGAM will be given at 26-28 weeks)

21

Test Significance / Course of Action: VDRL and RPR

Treat if positive; retest at 36 weeks

22

Test Significance / Course of Action: Rubella Titer

If titer is 1:8 or less, mother is not immune. Immunize post-partum if not immune.

23

Test Significance / Course of Action: Hemoglobin Electrophoresis

If mother is positive, check partner. Infant is at risk only if both parents are positive.

24

Test Significance / Course of Action: Hepatitis B

If present, infants should be given hepatitis immune globulin and vaccine soon after birth.

25

HIV Screen

Positive results require retesting, counseling, and treatment to lower infant infection

26

Test Significance / Course of Action: Urinalysis

Requires further assessment if positive for more than trace:

• Protein (renal damage, preeclampsia, or normal)
• Glucose (diabetes or normal)
• Ketones (Fasting or dehydration)
• Bacteria (Infection)

27

Test Significance / Course of Action: Pap Test

Treat and refer ib abnormal cells are present

28

Test Significance / Course of Action: Cervical Culture

• Treat and retest as necessary.
• Treat GBS during labor.

29

Test Significance / Course of Action: Triple Screen

Abnormal results may indicate Down Syndrome or neural tube defects.

30

Test Significance / Course of Action: Maternal Blood Glucose

If elevated, a 3-hour glucose tolerance test is recommended.

31

Test to be done in the 1st trimester

nuchal translucency screening +PAPP-A

32

When should the MSAFP Triple / Quad Screen be administered?

15-22 weeks

33

When should an ultrasound to check fetal anatomy be administered?

18-20 weeks

34

What five tests should be done at the 28 week visit?

• CBC
• Antibody screen
• RPR (Rapid plasma regain)
• GCT
• Rhogam

35

What four tests should be done at the 36 week visit?

• CBC
• RPR (Rapid plasma regain)
• GC/CT
• GBS vaginal culture

36

What does MSAFP stand for

Maternal screen for Alpha-Fetoprotein

37

What is AFP?

Alpha-Fetoprotein: the main protein in fetal plasma

38

Where is AFP?

• Diffuses from fetal plasma into fetal urine and is excreted into the amniotic fluid.
• Some AFP crosses placental membranes into the maternal circulation. Therefore, AFP can be measured both in maternal serum (MSAFP) and amniotic fluid (AFAPFP)

39

Abnormal concentrations of AFP -- implications

Associated with serious fetal anomalies, requiring additional testing to determine the reason for the abnormal concentration.

40

Levels associated with neural tube defects

Elevated AFP indicates NFP

41

Levels associated with down's syndrome (3)

• Low AFP
• Low Estriol
• Elevated hCG

42

Recommendations: Abnormal triple screen (3)

• Genetic counseling
• Ultrasound
• Amniocentesis

TRIPLE SCREEN IS NOT DIAGNOSTIC

43

Amniocentesis (def)

Aspiration of amniotic fluid, wihch contains fetal cells

44

When is an amniocentesis typically performed?

After 14 weeks, in 3rd trimester

45

Purpose of amniocentesis (3)

DIAGNOSIS of prenatal anomalies
• Genetic disorders / anomalies
• Pulmonary maturity (3rd trimester)
• Fetal hemolytic disease

46

Indications of amniocentesis (5)

• Maternal age >35
• History of child with chromosomal abnormality
• Family history of chromosomal abnormalities
• Inherited disorders of metabolism
• Abnormal triple screen

47

Complications involved with an amniocentesis: Prevalence

• Occur in <1% of cases

48

Complications involved with an amniocentesis: Maternal

Hemorrhage

49

Complications involved with an amniocentesis: Fetal (6)

Fetal death secondary to...
• Hemorrhage
• Infection
• Direct injury from needle
• Miscarriage
• PTL
• Leakage of fluid

50

Chorionic villus sampling: Purpose

DIAGNOSTIC TOOL
• Used to diagnose fetal chromosome or metabolic abnormalities

51

Chorionic Villus sampling: What can it NOT diagnose?

• Cannot diagnose anomalies for which amniotic fluid is essential (eg open neural tube defects, which require measuring AFP levels)

52

Chorionic Villus sampling: Method

• Removal of small tissue specimen from fetal portion of the placenta
• Performed transcervically or transabdominally

53

Chorionic Villus sampling: Benefit

• Allows for early diagnosis and rapid results

54

Chorionic Villus sampling:When performed

10-12 weeks

55

Chorionic Villus sampling: Complications (6)

• Vaginal spotting or bleeding
• Miscarriage (0.3%)
• Rupture of membranes (0.1%)
• Chorioamnioitis (0.5%)
• Maternal-fetal hemorrhage
• Limb deformities

56

Fetal movement counts (def)

Movements by the fetus, as assessed by the mother: “Kick counts”

57

Fetal movement counts -- Reason

Fetal movement is associated with fetal condition. Daily evaluation of these movements provides a way for evaluating the fetus.

58

Fetal movement counts -- Timing

Begins at 28 weeks; recommended daily.

59

Fetal movement counts-- Advantages (3)

• Inexpensive
• Non-invasive
• Convenient for client, encourages participation in care

60

Fetal movement counts-- Disadvantages (4)

• Fetal resting state normally decreases movements
• Maternal perception of fetal movement varies widely; even in the same woman at different times.
• Time of day may affect movement (less in the morning, greater in evening)
• Maternal use of drugs (sedative drugs, methadone, heroine, cocaine, alcohol, tobacco) may affect fetal activity.

61

Non-Stress Test: Purpose

To assess fetal well-being:
• Evaluation of fetal response (fetal heart rate) to natural contractile uterine activity or an increase in fetal activity
• Fetus will produce characteristic heart rate patterns in response to fetal movement

62

What causes a diminished fetal response? (4)

• Hypoxia
• Acidosis
• Drugs
• Fetal sleep cycle

63

Benefits of Non-Stress Test (2)

• Non-invasive
• No contraindications

64

NST: Interpreting Results (3)

• Reactive: Two accelerations in 20 minutes
• Non-reactive: Doesn’t meet criteria for reactive
• Unsatisfactory: Cannot identify baseline (marked variability) or technical problems / poor tracing

65

Contraction Stress Test: Function (2)

• Identifies the fetus who is compromised, under stress
• Used to identify the jeopardized fetus that was stable at rest, but showed evidence of compromise after stress

66

Contraction Stress Test: What to identify (3)

o Must identify fetal baseline, moderate variability, and the possible occurrence of spontaneous contractions.

67

Contraction Stress Test: Methodology

• Uterine contractions are stimulated
• When adequate contractions or hyperstimulation occurs, stimulation is stopped

68

Contraction Stress Test: What would indicate fetal distress?

LATE DECELERATION

o Uterine contraction decreases uterine blood flow and placental perfusion

• If the decrease is sufficient to produce hypoxia in the fetus, a deceleration in FHR will result, beginning at the peak of the contraction and persisting after its conclusion (late deceleration).

69

Contraction Stress Test: Interpreting Results

• Negative CST: No decelerations with contractions
• Positive CST: Repetitive decelerations with contractions

70

Contraction Stress Test: How are uterine contractions stimulated? (2)

• Nipple stimulation: Warm cloth applied to both breasts for 10 minutes, then massage the nipples for ten minutes
• Oxytocin: Given IV to stimulate contractions

71

Hyperstimulation (def)

Contractions lasting more than 90 seconds or five or more contractions in 10 minutes.

72

Biophysical Profile: Methods (2 components)

• Ultrasound – uses real-time ultrasound that enables monitoring of fetal biophysical responses to stimuli
• External fetal monitoring

73

What is the fetal response to central hypoxia? (BPP)

Alteration in movement, tone, breathing, HR

74

Biophysical Profile: Five components measured

• Fetal breathing movements
• Gross body movements
• Fetal tone
• Fetal heart rate
• Amniotic fluid volume

75

Biophysical Profile: Results (3)

• Normal: 8-10 if AFV is WNL
Indicates CNS if functional, fetus is not hypoxemic

• Equivocal: 6

• Abnormal: <4 with abnormal AFV. Induction indicated.

76

What tool is used to measure amniotic fluid?

Ultrasound

77

What does the AFI measure?

Depth in cm of amniotic fluid in all four quadrants

78

AFI: Normal / Abnormal (3)

• Normal range: Between 5cm and 20 cm
• Oligohydraminos: 20cms

79

Ultrasounds: 2 types

o Abdominal
o Transvaginal

80

Abdominal ultrasound (2 characteristics)

• More effective after 1st trimester
• Must have a full bladder

81

Transvaginal ultrasound (2 characteristics)

• Optimal during 1st trimester
• Bladder can be empty

82

What does a first trimester sonogram indicate? (5)

o Number, size, location of gestational sacs
o Presence or absence of fetal cardiac and body movements
o Uterine abnormalities or adenexal masses
o Estimated gestational age (EGA)
o Presence and location of IUD

83

What does a 2nd / 3rd trimester sonogram indicate?

o Fetal viability
o Number of fetuses
o Gestational age, growth pattern
o Fetal anomalies
o Amniotic fluid volume (AFV)
o Placental location and maturity
o Fetal position
o Uterine fibroids and anomalies
o Adnexal masses
o Cervical length