Red Cell Antibody GTG Flashcards
What % of pregnancies have red cell antibodies?
1.2%
1 in 80
What % of women have clinical significant red cell antibodies?
0.4%
1 in 300
Which antibody is most common to have in pregnancy?
Anti-D
Which antibodies have severe risk of haemolytic disease of the foetus and newborn (HDFN)?
Anti-
D
c
K
c+E
When should women be screened for antibodies?
Booking and 28 weeks
Non invasive testing for fetal genotype is available for which antigens?
D, C, c, E, e and K antigens
This should be perform in 1st instance if relevant red cell antibody detected in mother
If antibody detected in mother and fetal anaemia is a concern, how can the fetal antigens be tested?
(Not D, C, c, E, e and K antigens)
Consider CVS ir amniocentesis if fetal anaemia is a concern.
Should not perform if alloimmunisation has already occured
When is non invasive fetal genotyping performed?
From 16 weeks, except K which is from 20 weeks.
When should you refer to FMU?
Rising levels
Above specific threshold
USS suggestive of fetal anaemia
Anti-D:
Which threshold is considered moderate risk and FMU referral should take place.
What threshold for severe risk HDFN
If >4
> 15 indicates severe risk HDFN
Anti-c:
Which threshold is considered moderate risk and FMU referral should take place.
What threshold for severe risk HDFN
> 7.5
> 20
Anti-K:
When should be referred to FMU
Refer if detect, even if risk HDFN low
Anti-E, when to refer?
Refer if in presence with anti-c
For antibodies other than D/c/K, when to refer
Previous HDFM or IUT
Rising titres
Titre >32
If Anti-D/c/K present, how often should levels be monitored?
Every 4 weeks until 28 weeks then every 2 weeks until delivery
