Term
| what are three names for the condition caused by alloimmunization, which is the most appropirate |
|
Definition
hemolytic disease of the newborn
erythroblastosis fetalis
hemolytic disease of the fetus and newborn - best |
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|
Term
| what is another name for alloimmunization |
|
Definition
|
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Term
|
Definition
| exposire to foreign red cell antigen causes production of anti-red cell antibodies |
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|
Term
| what are the adverse effects of alloimmunization 3 |
|
Definition
fetal anemia
hyperbilirubinemia
hydrops fetalis |
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|
Term
|
Definition
| abnormal build up of fluid in 2+ fetal compartments |
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|
Term
| what are the conditions that must be met for alloimmunization to occur |
|
Definition
fetal blood group factor inherited from dad that mom dosent have causes response in mom
any mechanism of transplacental passage of fetal cells allows activation (bleeding, maternal placental barrier dysruption) |
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|
Term
| what are the antigens of the Rh antigen system |
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Definition
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|
Term
| what antigen stands for "Rh" |
|
Definition
Rh+ means D antigen positive
Rh- means D antigen negative |
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|
Term
| what is always the first step in alloimmmunization management and diagnosis |
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Definition
| determine blood type of mother and father |
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|
Term
| how do you determine alloimmunization if the father is unknown |
|
Definition
| amniocenesis to determine fetal antigen type |
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|
Term
| what does anti-D IgG to (biochem explination) |
|
Definition
non-agglutinating antibody that does not bind complement
causes a lack of intravascular hemolysis |
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|
Term
| what blood type is needed to acuse alloimmunization |
|
Definition
|
|
Term
| explain what happens in alloimmunization in first pregnancy |
|
Definition
sensitization that causes harm is rare
RBC may never be encountered UNTIL DELIVERY
maternal IgM to Rh+ is made but cannot cross placenta |
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|
Term
| how much fetal blood is needed to cause alloimmunization, what is the percent chance |
|
Definition
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|
Term
| explain what happens in the 2nd pregnancy in alloimmunization |
|
Definition
mom has made IgG which can cross placenta
maternal antibodies will enter fetal circulation and attach to Rh+ fetal RBC
antibody coated cells are destoried in fetal liver and spleen causing anemia |
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|
Term
| what causes alloimmunization to worsen |
|
Definition
| worsens with each pregnancy |
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|
Term
| what events causes a 3% or less risk of Rh sensitization 3 |
|
Definition
ectopic pregnancy
full term PREGNANCY
amniocentesis |
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|
Term
| what events cause a 3-6% risk of Rh sensitization 2 |
|
Definition
spontaneous abortion
induced abortion |
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|
Term
| what events cause a 14-17% risk of Rh sensitization 2 |
|
Definition
full term DELIVERY
ABO compatability/incompatability |
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|
Term
| what events cause a 90-95% risk of Rh sensitization 1 |
|
Definition
| mismatched transfusion: mom was previously sensitized when wrong blood was transfused to her previously (can make 1st pregnancy response more like 2nd because mom has IgG) |
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|
Term
| what are causes of Rh sensitization risk without a percent association 4 |
|
Definition
placental abruption
previx
abdominal trauma
external cephalic version |
|
|
Term
| define placental abruption |
|
Definition
| bleeding between placenta and uterus |
|
|
Term
|
Definition
| part of placenta completely or partially covers cervix (causes bleeding |
|
|
Term
| define external cephalic version |
|
Definition
| manual flipping of baby for positioning |
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|
Term
| what are the severity of the effects on the baby determined by in Rh sensitization |
|
Definition
| amount of antibody that crosses placenta and ability of fetus to replace destoried cells |
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|
Term
| what are the effects of Rh sensitization on a baby in mom's 1st pregnancy 2, why |
|
Definition
mild anemia
elevated bilirubin: liver cant metabolize and excrete released bilirubin from destoried RBC |
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|
Term
| tx of Rh sensitization after 1st pregnancy 2 |
|
Definition
UV light
exchange transfusion |
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|
Term
| what are the effects of Rh sensitization on the baby in mom's 2nd pregnancy 9 |
|
Definition
rate of RBC destruction is accelerated
anemia is worse
hydrops fetalis due to anemia
hematopoesis in alt sites
decreased liver function
lower oncotic pressure
decreased Hb
CO increases to compensate for O2 delivery lack
increased 2,3-BPG causes tissue hypoxia |
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|
Term
| what are the signs of hydrops fetalis 4 |
|
Definition
ascites
SC edema
pleural effusions
high output cardiac failure |
|
|
Term
| what is the cause of hydrops fetalis in Rh sensitization |
|
Definition
|
|
Term
| what are the signs of decreased liver function in Rh sensitization 3 |
|
Definition
RBC production in liver declines
decreased proteins lower oncotic pressure and increase intravascular resistance |
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|
Term
| in Rh sensitization Hb is lowered in fetus, what happens when Hb is less than 2, 4, 7, 8 d/dl |
|
Definition
2: reticulocytosis in marrow
4: increase in venous lactate causes hydrops fetalis
7: erythroblasts release from liver
8: umbilical artery lactate level increases |
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|
Term
| why does Rh sensitization cause hydrops fetalis 5 |
|
Definition
increased venous lactate due to low Hb
enhanced hepatic erythropoietic function with depressed synthesis of serum proteins
tissue hypoxia due to anemia enhances capillary perfusion
Fe overload due to ongiong hemolysis causes ROS and endothalial cell dysfunction
functional blockage of lymph system at level of thoracic duct as it empties into left brachiocephalic vein |
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|
Term
| how is Rh sensitization diagnosed |
|
Definition
hx of previous sensitization pregnancy
ABO/Rh blood type status and titers |
|
|
Term
| what Rh antibodies are significant for Rh sensitization which are not (5 total) |
|
Definition
lewis- lives
kell- kills
duffy (Fya) - dies
duffy (Fyb) - ok
D - dies |
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|
Term
| what information can an antibody titer give you about Rh sensitization |
|
Definition
reflect strength and amt of maternal antibody response, helps determine if AB response is strong enough to cause risk of fetal anemia
provide NO info about fetal status |
|
|
Term
|
Definition
point where titer is significant to pose risk for FHD and hydrops
1:8-1:32 |
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|
Term
| what does it mean if a Rh titer is <1:8 |
|
Definition
| Rh-D negative pt can be monitered with serial titer assessments every 4wks |
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|
Term
| how can a titer help in a mom with a hx of Rh sensitization |
|
Definition
|
|
Term
| what is the best indication of fetal condition in Rh sensitization |
|
Definition
level of bilirubin in amniotic fluid
it is supposed to decrease progressivly in 2nd half of gestation |
|
|
Term
| how is bilirubin measured |
|
Definition
|
|
Term
| what does a liley curve plot, what changes the plot (what is the indicator) |
|
Definition
optical density vs gestational age
bilirubin causes deivation of curve at 450 nm |
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|
Term
| what is the degree of deviation in a liley plot called, why |
|
Definition
| delta 450, this is when bilirubin causes deviation of curve indicating levels are too high |
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|
Term
| what is the indication on a liley curve that a fetal blood sample needs to be evaluated |
|
Definition
| OC-D 450 in 80th percentile of zone 2 |
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|
Term
| how is a liley curve read |
|
Definition
three zones based on gestational age up to 27wks
upper U zone: severly effected
middle M zone: moderatly affected
lower L zone: minimally affected |
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|
Term
| what does a queenan curve plot, why do we use it |
|
Definition
| same as liley but goes through early second trimester (past 27 wks) |
|
|
Term
| what does a MCA doppler ultrasound measure, what does it tell us |
|
Definition
peak velocity of middle of cerebral artery
increased velocity means increased fetal anemia |
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|
Term
| other than Rh sensitization, what is increased doppler velicity associated with |
|
Definition
| low blood viscosity due to shearing forces on vessels |
|
|
Term
| what does severe anemia do the a fetal heart |
|
Definition
|
|
Term
| what are the three principals used to correlate peak velicity in doppler to fetal anemia |
|
Definition
| value >1.5 multiples of median for corresponding gestational age perducts moderate to severe fetal anemia with a sensitivity of 88% and negative perdictive rate of 89% |
|
|
Term
| when are doppler measurements reliable in gestation |
|
Definition
|
|
Term
| how often should doppler be done on fetus |
|
Definition
|
|
Term
| other than fetal anemia, what can dopplers tell us 3 |
|
Definition
SC edema and ascites presence
BPP (biophysical profile): fetal well being
AFI |
|
|
Term
| how can moderate to severe fetal anemia be determined (it's too much for doppler), how does it work |
|
Definition
PUBS: transfusion of antigen-negative RBC for hCT <30%
direct transfusion under ultrasound guidance into umbilical vein is prefered
timing and need for more transfusions based on severity of disease |
|
|
Term
| how is fetal blood sampling done, what info can it give us 5 |
|
Definition
percutaneous imbilical sampling / cordcocentrsis
fetal blood type, HCT, direct coombs test, reticulocyte count, total bilirubin |
|
|
Term
| why dont we just do PUBS on all babies 2 |
|
Definition
1-2% risk of fetal loss
50% risk for FMH and worsening of alloimmunization |
|
|
Term
| who gets PUBS to check for allioimmunization 2 |
|
Definition
ELEVATED PEAK DOPPLER VELOCITIES
elevated change in OD-450 value |
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|
Term
| how can Rh sensitization be prevented 4 |
|
Definition
RhoGAM: no thimerosal for bacteria/fungi contaimination
hyperRho S/D
WinRhi-SDF: prepared through sepharose column
rhophlac: prepared through ion exchange ehromotography |
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|
Term
| how can rhoGAM be administered |
|
Definition
| IM through human plasma throguh Cohn cold ethanol fractionation |
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|
Term
| what are the next frequent sensitization problem causing antibodies after anti-Rh-D in order 5 |
|
Definition
|
|
Term
| indications for rhogam with no evidence of anti-D alloimmunization in Rh-D negative woman |
|
Definition
300 ug at 28 wks (sart of 2nd trimester)
repeating antibody screen at 28 wks before giving rhogam is contriversal (up to doc)
re-administer if stil pregnant at 40wks |
|
|
Term
| level A evidence for giving rhogam 9 |
|
Definition
spontaneous abortion
elective abortion
actopic pregnancy
genetic amniocentesis
amniocentesis for fetal lung maturity
chorion villous sampliing
fetal blood sampling
28wk gestation unless dad is Rh-
within 73h of deliver if fetus is Rh+ |
|
|
Term
| level B evidence for giving rhogam 1 |
|
Definition
|
|
Term
| level C evidence for giving rhogam 8 |
|
Definition
threatened abortion
fetal death in 2/3rd trimester
intrauterine fetal demis
blunt trauma to abdomen (includes MVA)
suspected abruption
external cephalic version
placenta preva with bleeding
after administration of RhD positive blood components |
|
|
Term
|
Definition
|
|
Term
| what is the anti-D titer by term in pt who got rhogam |
|
Definition
| 15-20% had titer that was low (2-4) |
|
|
Term
|
Definition
| manual vaccume aspiration |
|
|
Term
| if fetus is Rh+ how much rhogam should be given and when |
|
Definition
| 300ug within 72h of birth |
|
|
Term
| how much fetal blood does 300ug rhogam protect against |
|
Definition
|
|
Term
|
Definition
| calcuate how many fetal cells are in circulation to determine how much rhogam is needed to cover them |
|
|
Term
|
Definition
| fetal maternal hemorrhage |
|
|
Term
| what does the kleihauer betke test test for, how |
|
Definition
maternal blood subject to KOH
cells sensitive to changes in pH and immediatly lyse and become ghost cells
fetal cells are more resistant and remain latent
ratio of fetal to maternal cells per 1000 cells counted
300 ug rhogam neutralizes 15cc of fetal red cells |
|
|
Term
| what do you do if mom has positive antibody screen for Rh sensitization |
|
Definition
Rhogam wont work, she is already sensitized
you do dopplers and minotor
iv velocity is elevated you need to do invasive testing
lets be real you have no clue, just refer them |
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