Mom & Baby test Flashcards

1
Q

Prenatal type & screen

A
  • Early in the pregnancy
  • ABO & Rh: to determine RhIG and for weak D
  • Screen: For other unexpected RBC antibodies
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2
Q

RhIg program

A
  • For Rh negative parent
  • At 28 weeks with a presumption that baby is Rh pos
  • Following miscarriage, abortion, trauma, invasive procedure
  • Within 72 hrs of delivery:
    + Baby: D pos, weak D pos, unknown Rh
    + Parent is not already sensitized D antigen
  • Show up in AbSC
  • Prenatal sample collected prior to RhIG administration
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3
Q

If a prenatal AbSC is positive

A
  • Perform Ab ID
  • Titer Ab if IgG: serial dilution, homozygous cell, significant if > 16 ( for K, significant >8), repeat throughout the pregnancy
  • Paternal phenotype (uncommon)
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4
Q

Methods to monitor the fetus

A
  • Ultrasound: check hydrops (increase body fluid)
  • Amniocentesis: phenotype the baby, measure the amniotic fluid at OD 450nm (for bilirubin) –> increase risk of miscarriage
  • Cordocentesis: measure the Hgb in the cord blood –> increase the risk
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5
Q

Intrauterine transfusion (IUT)

A
  • Baby lost blood due to HDFN
  • Indication: OD450nm in zone 2, 3 / Hgb < 10g/dL / fetal hydrops detected
  • Try to give fetus more time
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6
Q

Requirements for IUT

A
  • Irradiated (prevent TA-GvHD)
  • Leukoreduced
  • < 5 days old
  • O neg
  • Antigen compatible with parent
  • Hgb S neg
  • Modification (volume reduction, wash)
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7
Q

Postnatal test

A
  • TSCR on the parent: in case need to transfusion
  • Baby: ABO/D & Weak D for baby Rh neg (confirmation) and parent is a candidate for RhIg
  • Sample from baby: cord cell, heel stick, line draw
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8
Q

Challenge for newborn testing

A
  • Parental contamination
  • Mixed field in ABO: contamination and incomplete expression of A & B antigen
  • Parental Antibodies coat baby’s cells –> Invalid ABO due to positive control.
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9
Q

DAT on baby

A
  • Only IgG concern
  • May detect ABO HDFN: mom is O and makes anti-A,B Ab. DAT on baby can be weak due to incompleted antigen
  • DAT is positive –> perform eluate
  • Elution: use cord cells –> test with AbSC and AbID
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10
Q

Test for Rh- parent and Rh+ baby

A
  • Determine candidacy for RhIg therapy
  • Optimal: 1 hour post-delivery
  • Screening test: Fetal bleed screen
  • Enumeration test: KB or Flow cytometry
  • Determine RhIg dosage
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11
Q

FBS (Rosette test)

A
  • Will detect > 10ml of fetal blood in parental circulation
  • Use parent’s blood
  • Chemically modified Anti-D
  • Incubate - Wash - Add indicator cells - Observe on microscope
  • Positive (> 5 agglutinin in 5 fields)
  • -> perform enumeration test: KB or Flow cytometry
  • Negative (< 5 agglutinin in 5 fields)
  • -> 1 dose of RhIG
  • Can’t use of parent or baby is weak D (false negative result)
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12
Q

KB test

A
  • Acid destroy parental Hgb but not fetal cells –> stain on smear. Fetal cell: pink & adult cells: ghost
  • Count total 2000 cells –> % of fetal cells
  • Cons: error due to fetal cells & lymphocytes, not precise, Hgb F can cause false elevated
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13
Q

Flow cytometry

A
  • Anti-Hgb F
  • Precise
  • Expensive
  • Can used for Rh pos parent
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14
Q

RhIG

A
  • 1 dose (300mcg) = 30mL WB or 15mL packed RBC
  • Given within 72 hours and not exceed 5 doses (IM per 24 hour). If need larger dose –> IV
  • Cleared within 6 months
  • RhIG at delivery: 2% make alloAb
  • RhIG at w28 and delivery: 0.2% make alloAb
  • Mini dose (50mcg): effective only 1st trimester
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15
Q

Monitoring of baby

A
  • Anemia, bilirubin –> prevent kernicterus (bilirubin > 25 mg/dL)
  • Treatment: bili-light (no effective if bilirubin rises at a rate 0.5-2.0mg/dL/h). Exchange transfusion (perform when serum bilirubin at 18-20mg/dL)
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16
Q

Transfusing baby

A
  • Same with IUT
  • Pedi-pack or aliquot
  • 90% low birth weight and 58% of preterm infant
  • Exchange transfusion: reconstituted RBC (mix RBC and plasma)
17
Q

Hydrop fetalis

A
  • Hight cardiac output –> accumulation of extracellular fluid
  • 30% mortality: stillbirth or neonatal
18
Q

Newborn jaundice

A
  • Jaundice
  • Bilirubin pass though blood/brain barrier
  • Acute bilirubin encephalopathy
  • Kernicterus
19
Q

Cause of maternal fetal hemorrhage

A
  • term, preterm delivery
  • miscarriage
  • Abortion
  • ectopic pregnancy
  • chronic villi sampling
  • amniocentesis
  • vaginal bleeding
20
Q

Titer prenatal testing

A
  • Report as too weak or 1:2, 1:4, 1:8
  • Titer value: the reciprocal of the last tube dilution that demonstrates a positive agglutinin reaction
  • Critical titer: titer at which there’s a significant risk for hydrops fetalis (at UW 1:8)
  • If < 1:8, perform monthly titer during pregnancy, except anti-K
21
Q

Other prenatal tests

A
  • Type parent’s partner (homozygous, heterozygous)
  • Fetal testing
  • Cell free DNA: fetal Rh status 96-99%, use maternal blood
  • Amniocentesis
22
Q

Postnatal test

A
  • Incompatible blood types mom & baby
  • Hemolysis?
  • Antibody-mediated hemolysis
23
Q

Ultrasound

A
  • Anemia cause increased cardiac output
  • Lower blood viscosity –> increase blood velocity
  • Measure o the fetal middle cerebral artery (MCA)
  • Value > 1.5 MoM –> moderate to severe fetal anemia
  • Start at 18-20 weeks (after 35w, maybe false positive)
  • Non-invasive and can be used for Kell
24
Q

Intrauterine Transfusion

A
  • O neg, CMV negative, irradiated
  • Fresh unit has higher 2,3 DPG
  • HCT 70-80
  • Fetal monitoring
  • Transfuse 40-100 cc
  • Lab: opening and closing HCT
  • Transfuse q2 weeks for 1st two and q3 weeks up to 35 weeks
25
Q

Neonatal Management after IUT

A
  • IUT will suppress fetal erythropoesis
  • Deliver at 37-38 weeks
  • At birth need: IAT, DAT, HCT, Reticulocyte count, bilirubin
  • Follow up HCt & reticulocyte counts until recovery of hematopoietic function (4-6 weeks)
26
Q

ABO-induced disease

A
  • Infant A, B from O mom
  • Can occur in 1st pregnancy
  • 15% of all pregnancies (only 0.6% need treatment)
27
Q

Neonatal Management (hemolysis)

A
  • Oral hydration
  • Phototherapy
  • Blue light (420-470)
  • Converts bilirubin to lumirubin (soluble –> excreted into bile and urine)
  • Simple transfusion
  • Immunoglobulin therapy
  • Exchange transfusion
28
Q

Postpartum hemorrhage

A
  • Within 24 hrs after delivery (> 1000mL)
  • Secondary if happen after 24 hrs to 6-12 weeks
  • 1-5% of deliveries
  • Uterine atony most common
29
Q

Invasive Placentation

A
  • Abnormal placentation: attachment of placenta to uterine lining
  • Directly attach to myometrium
  • Risk: previous C-section, uterine surgery, placenta previa
30
Q

Placenta abruption

A
  • Premature separation of placenta from the uterus

- Bleeding leads to placental separation

31
Q

Obstetric Bleeding Emergency Protocol

A

RBC: FFP:PLT ( 6 unit each) and 10 unit of cryoprecipitate

32
Q

Transfusion Indication for Obstetric

A
  • Massive hemorrhage: RBC, 4u FFP if needed
  • PLT < 100K: 6 packs
  • Fibrinogen < 125: 6 unit cryo
  • INR > 1.5: 4 unit FFP