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Hey so i got the basics of RH incompatibility but still a little lost please clear my mistakes

Mom first prenatal screen do RH Ab screen
Shes Rh - so we do titer.. if shes unsensitized then aka no Antibodys then give her Rhogam at 28 weeks or any time any bleeding happens and then again within 72 hours post delivery...

Now say shes is RH- and titer is + this is where im lost... if the titer is less than 1:4 then we treat her like an unsensitized pt... aka Rhogam when time comes.
If its less then 1:16 we dont do anything aka just F/U monthly.. Doubt Kaplan says 1:8 MTB is 1:16 whats right?

But if her titer is >1:16 or reaches that point we do amniocentesis and if fetus is RH - we evaluate.

Do we do MCA doppler first cuz its less invasive? Or Fluid Bili or PUBS(or do we do PUBS after high Fluid Bili or can do do it separately?) Lost here and

Lost with if MCA< 1.5 how to manage it and what are the low or normal values for it? I know Bili fluid is low we repeat it every 2-3 weeks and for Med its 1-2 weeks F/u.

After those test if MCA is >1.5 or Bili is High or PUBs HCt is 34 weeks

I know its a lot if someone can clear up my grey areas and if theres any mistakes let me know thanks a lot this is the one thing that always bugs me....

??? Anyone

Ur 1st q>
Do we do MCA doppler first cuz its less invasive? Or Fluid Bili or PUBS(or do we do PUBS after high Fluid Bili or can do do it separately?) Lost here
----MCA Doppler velocity has proven to be a reliable screening test to detect fetal anemia and can be started as early as 18 weeks but not reliable after 35 weeks GA (i dont know why)

Kaplan has just mentioned either MCA or amniocentesis or PUBS
(So i guess that is all needed for our level)

Ur 2nd q>
Lost with if MCA< 1.5 how to manage it and what are the low or normal values for it? I know Bili fluid is low we repeat it every 2-3 weeks and for Med its 1-2 weeks F/u.

Ans--- if MCA flow is elevated then that indicates severity of anemia (not decreased flow) ,as anemia worsens peak flow velocity rises!!
(Dont know about exact value for MCA)

I will give you my summary from kaplan and mtb about what i read and understood---

RH incompability management::

- do prenatal screening test for antibody titer: 28-35 weeks
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1st
if Antibody titer less than 1:4-- mother is unsensitized-- give RHogam standard dose i/m @28 weeks.
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After delivery if baby is RH positive estimate fetal maternal hemorrhage (FMH) by doing Rosette test (qualitative test that helps to determine FMH)

* if rosette test is negative:: --- give standard dose of i/m Rhogam again
* if rosette test is positive ---- do kleihaur betke test ( quantitative test to determine the amount of FMH)
Or fetal cell stain using flow cytometry
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Usu 300 microgram of Rhogam neutralize 15 ml of fetal rbc

Therefore for every 15 ml of FMH increase the dose of Rhogam


2nd
Ifantibody titer is 1:8-- go with conservative management i.e repeat titer monthly as long as it remains less than 1:8.
Also, give Rhogam standard dose i/m , follow above!!


3rd
if antibody titer is more than 1:16 do amniocentesis at 16-20 weeks.
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*If fetal cells RH negative--- manage like normal pregnancy

* if fetal cells RH positive do amniocentesis again to determine fetal level of hemolysis by measuring bilirubin
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Follow lily graph
* if low bilirubin level (zone 1)- -- no or mild anemia --- repeat amniocentesis in 2-3 weeks
*if medium bilirubin level (zone 2)---- moderate anemia ---repeat amniocentesis 1-2 weeks
* if high bilirubin (zone 3)--- high anemia risk ---- do PUBS or usg Doppler -----if fetal hematocrit is low (less than 25%) or MCA flow elevated follow below
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If GA less than 34 weeks: perform intrauterine intravascular transfusion

If GA more than 34 weeks : perform delivery



Also , give Rhogam within 72 hours if there is
-amniocentesis
-chorionic villus sampling
- D&C
- vaginal bleeding and abortion

U may require higher than usual dose of Rhogam in the above cases as per FMH quantity
So any failure to correct the dose of anti-d immunoglobulin may result in maternal alloimmunization!!

ok thanks a lot