Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

CLS > HDFN > Flashcards

HDFN Flashcards

1
Q

Destruction of RBCs of the fetus by antibodies produced by the mother

A

Hemolytic Disease of the Fetus and Newborn (HDFN)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What class of Ig is actively transported across the placenta?

A

IgG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

How much blood is needed to immunize the mom?

A

1 ml (20 drops)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is the factor that affects immunization and severity?

A

Fetomaternal hemorrhage during pregnancy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What occurs during fetomaternal hemorrhage during pregnancy?

A

Significant increases in maternal antibody titers leading to increased severity of HDFN

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What method is used to determine fetal hemoglobin?

A

Acid-elution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What increases the risk of fetomaternal hemorrhage?

A

Amniocentesis, chorionic villus sampling, and trauma to the abdomen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

When does active transport of IgG begin?

A

Second trimester and continues until birth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Which immunogen is the most antigenic?

A

D

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are other potent Rh immunogens of HDFN?

A

C, c, E

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What is the most clinically significant non-Rh antibody able to cause HDFN?

A

Anti-K

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Do you still work up Anti-Lewis for HDFN?

A

Yes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are the common antibodies identified in prenatal specimens that cause HDFN?

A

Rh series and Kell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What the rare antibodies identified in prenatal specimens that cause HDFN?

A

Anti-Fya, Anti-Jka, Anti-MNSs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What antibodies never cause HDFN?

A

Anti-Lewis, I, IH, P1

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What happens during hemolysis in HDFN?

A

Maternal IgG attaches to specific antigens of fetal RBCs –> the antibody coated cells are removed by macrophages of the spleen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is the rate of destruction of fetal RBCs when the maternal IgG attaches?

A

Depends on antibody titer and specificity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What happens during RBC destruction?

A

Release of hemoglobin, which metabolizes bilirubin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is done during the first prenatal visit (1st trimester)?

A

Type and screen (including weak D)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What must be able to be detected during type and screen?

A

Clinically significant IgG alloantibodies reactive at 37C and in antiglobulin phase

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What happens if the screen is negative during the 1st prenatal type and screen?

A

Repeat testing prior to RhIg therapy (28 weeks/3rd trimester)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What happens if the screen is positive during the 1st prenatal type and screen?

A

Antibody must be identified

  • can ignore IgM antibodies
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What happens when the screen was initially negative but now positive during the/after the 28-week mark?

A

Reactive anti-D due to RhIg immunization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What should the father be tested for?

A

Presence of D antigen

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

What test should be done if the mother has anti-D and the father is heterozygous for D antigen?

A

Amniocentesis to check if baby is carrying D antigen, which can be performed as early as 10-12 weeks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What does the antibody titration tell you?

A

Antibody titration tells you the concentration of alloantibody

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What is done during an antibody titration?

A

Patient serum containing antibodies is serially diluted and tested against RBCs to determine the highest dilution at which a reaction occurs (MUST USE MONOCLONAL ANTI-IgG AHG FOR IAT)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

What is the result of the titration reported as?

A

A reciprocal of the titration endpoint

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

What titration is considered significant?

A

Titer of 16-32

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

What is it called when a fetus receives a blood transfusion through the umbilical vein in the placenta?

A

Intrauterine Transfusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

What is the goal of a intrauterine transfusion?

A

To maintain fetal hemoglobin above 10 g/dL

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

How often do you need to repeat intrauterine transfusion once initiated?

A

Every 2-4 weeks until 34-36 weeks gestation (or until fetal lungs are mature)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

What can intrauterine transfusion suppress?

A

Fetal bone marrow production of RBCs, so infant may need a transfusion after birth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

What serological tests are performed on a newborn?

A

ABORh (without reverse) & DAT with IgG reagent

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

What type of AHG reagent is used in a DAT for a newborn?

A

Monoclonal IgG AHG

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

Why is reverse typing not performed on a newborn?

A

Newborn’s isoagglutinins are the mother’s so there’s no point

37
Q

What happens when there’s a false negative RhD for the baby?

A

Since baby’s RBCs are heavily bound with maternal anti-D, an ELUATE is needed to type the baby’s RBCs for anti-D

38
Q

What happens when baby has a positive DAT?

A

There’s maternal IgG antibody coating infant’s RBCs, which causes false negative RhD

39
Q

What causes the false negative RhD for the baby?

A

If the baby’s D antigens are already bound to mom’s anti-D, it seems like there’s no D antigen for the D antisera to bind to.

40
Q

Why does a positive DAT invalidate Rh typing of baby?

A

Because it creates a false negative. There are anti-D antibodies attached to the D antigen, but it’s just not showing up.

41
Q

What is used to correct anemia when bilirubin level is not high enough to warrant an exchange transfusion?

A

Small aliquot transfusions

42
Q

What is used to remove high levels of unconjugated bilirubin?

A

Exchange transfusions

43
Q

What is done to prevent kernicterus (brain damage caused by bilirubin buildup) in newborns?

A

Exchange transfusions

44
Q

What else does exchange transfusions do besides remove bilirubin?

A
  • Remove antibody-coated RBCs of the baby, thereby preventing their destruction in vivo and an increase in bilirubin
  • Remove maternal antibody in circulation, preventing it from destroying newly produced RBCs
  • Correct anemia without causing volume overload
45
Q

Who is more affected at lower concentrations of bilirubin?

A

Premature infants rather than full-term infants

46
Q

What type of blood is often used for intrauterine and neonatal transfusions?

A

Type O

47
Q

What are the requirements for the blood used for intrauterine transfusions?

A

Type O NEG RBCs must be antigen-negative, CMV negative, less than 7 days old, irradiated to prevent GvHD, negative for HGB S, and compatible with mother’s plasma

48
Q

What units are given for fetuses and neonates whose blood types are unknown or Rh-negative?

A

Rh-negative units

49
Q

What should the hematocrit level of RBCs be for intrauterine transfusions?

A

more than 70%

50
Q

What type of blood preferred for exchange transfusions?

A

RBCs from WB units, IRRADIATED to prevent graft vs host disease, NEGATIVE for Hgb S, and LESS than 7 days old

51
Q

What type of plasma is used during exchange transfusions?

A

Plasma from group AB (no antibodies)

52
Q

What does RhoGam do?

A

Attaches to fetal Rh-positive RBCs in maternal circulation to prevent her from reading them and creating anti-D; so it only prevents cases due to anti-RhD

53
Q

When is RhoGam given?

A

28 weeks

54
Q

When is the dose present in screen?

A

10% of the antenatal dose will be present at 40 weeks gestation

55
Q

What calls for administration of RhoGam postpartum?

A

If the mom is non-immunized, Rh-negative & the baby is Rh positive (or weak D positive)

56
Q

Should you still give a non-immunized, Rh-negative mom RhoGam if she has a stillborn/miscarriage/abortion?

A

Yes, since baby’s blood type is unknown, just in case

57
Q

What happens if you don’t give Rh-negative mom RhoGam after delivery?

A

It’ll result in active immunization, so give within 72 hours of delivery

58
Q

Does administration of RhoGam count as active immunization?

A

No, it’s PASSIVE IMMUNIZATION and should NOT be mistakenly interpreted as active immunization; so while anti-RhD might be detected during delivery, an additional dose of RhoGam should still be given (if it’s really passive and no active)

59
Q

How must of a dose of RhoGam must be administered to all non-immunized, Rh-negative moms that give birth of Rh-positive babies?

A

300 ug (30cc) to protect against 1.5mL of pRBCs or 30mL of WB

60
Q

What is the total fetal blood volume at 12 weeks?

A

less than 5mL

61
Q

What is the dosage given for abortions or ectopic pregnancies?

A

Mini dose of 50 ug (less than 5cc)

62
Q

What is the Kleihauer-Betke Test for?

A

A quantitative test that estimates the amount of fetal-maternal hemorrhage (bleeding)

63
Q

When should more than one dose of RhoGam be administered?

A

When the degree of FMH (fetal maternal hemorrhage) is greater than 30mL of WB

64
Q

What is a screen test used to determine presence of a FMH?

A

Rosette Test

65
Q

What happens when the Rosette Test is positive?

A

Kleihauer-Betke test is needed to calculate the amount of fetal-maternal hemorrhage (bleeding)

66
Q

What is the limitation of Rosette Screening test?

A

The FMH must be 10cc or more and the mom has to be RhD-negative and the baby has to be RhD-positive

67
Q

What is the formula of Kleihauer-Betke?

A

[(fetal cells/total cells) x 5000mL] / 30mL = # of Rh doses/vials needed

**Rounded up or down then ADD 1 VIAL EXTRA*

68
Q

When is ABO HDFN often seen?

A

First pregnancy

69
Q

When is Rh HDFN often seen?

A

Second pregnancy

70
Q

What is the IgG seen in ABO HDFN?

A

Anti-A,B

71
Q

What are the IgG often seen in Rh HDFN?

A

Anti-D, Rh series, Kell

72
Q

During ABO HDFN, what is the range of bilirubin seen at birth?

A

Normal

73
Q

During Rh HDFN, what is the range of bilirubin seen at birth?

A

Elevated

74
Q

Is there anemia at birth for ABO HDFN?

A

No

75
Q

Is there anemia at birth for Rh HDFN?

A

Yes

76
Q

What is phototherapy used for?

A

For slowly rising bilirubin levels; to convert unconjugated bilirubin in both ABO and Rh HDFN and have it excreted in the urine

77
Q

Is exchange transfusion common in ABO HDFN?

A

Rare

78
Q

Is exchange transfusion common in Rh HDFN?

A

Sometimes

79
Q

Is intrauterine transfusion common in ABO HDFN?

A

No

80
Q

Is intrauterine transfusion common in Rh HDFN?

A

Sometimes

81
Q

Who is most at risk for ABO HDFN?

A

A (white) or B (black) infants with O mothers with potent anti-A,B

82
Q

Does mother’s history of prior transfusions or pregnancies relate to the occurrence and severity of ABO HDFN?

A

No

83
Q

What is exchange transfusion with O RBCs used for?

A

Rapidly increasing bilirubin levels

84
Q

When does bilirubin peak?

A

1 to 3 days

85
Q

What happens if you keep giving the baby blood during intrauterine transfusion?

A

You can suppress fetal bone marrow production of RBCs, so the baby may need a transfusion after birth

86
Q

Are high-titered IgG antibodies capable of causing significant RBC destruction in an ABO-incompatible fetus?

A

No, results in mild anemia or normal hgb levels

87
Q

When will ABO antigens be fully developed?

A

1 year after birth

88
Q

What is the number one cause of HDFN now?

A

ABO incompatibility in A or B babies with O mothers

89
Q

Does the severity of HDFN depend on positive DAT; or anti-A, anti-B, or anti-A,b in eluate of infant RBCs?

A

No

CLS (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions