Maternal Red Blood Cell Alloimmunization Flashcards
What is red blood cell alloimmunization?
Mother is exposed to new antigen from fetal RBC or transfusion and makes antibodies IgG that cross placenta and attack fetal blood cells
What 3 antibodies cause severe fetal anemia?
Kell, RhD, Rhc
How long can rhogam be given following bleeding or invasive procedure?
28 days
How much fetal blood transfusion does 300 ug of rhogam cover?
30 cc
What is the risk of alloimmunization if the protocol is not followed?
17% risk
When should you follow maternal titers in pregnancy?
If initial titer < 1:8
How often should you repeat titers in pregnancy?
< 24 weeks Monthly, > 24 weeks weekly
What is a critical titer?
> 1:8
Is there a critical titer for Kell antibody?
No, every positive titer is critical and should get MCA dopplers
When should you begin fetal MCA dopplers?
At critical titer
How often should you get MCA dopplers?
q 2 weeks
What is the concerning cutoff for MCA dopplers?
MCA > 1.5MoM
What is the next step in management if MCA > 1.5 MoM?
Fetal PUBS to determine HCT
What is the cut off for fetal HCT that would warrant an intrauterine transfusion?
Fetal HCT 30%
What is the first step in management of evaluating the risk of alloimmunization to the fetus in a mom who is Rh negative?
Determine paternal blood type
