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  #1  
Old 06-24-2011
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ObGyn When to do the Kleihauer-Batke test?

In isoimmunization if mother RH negative and her baby RH positive, we need to give her RHoGAM at 28 week as prophylaxis
so then after delivery should we give her RHoGAM again immediately
or do first Rosette test then kleihauer-batke test??

When we should do these tests ?

When we should give RHoGAM immediately without testing?
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Old 06-24-2011
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Read this
The Difference between Apt Test and Kleihauer-Betke Tests
although it might not answer your specific question but it's very useful.
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Old 06-24-2011
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Quote:
Originally Posted by kemoo View Post
In isoimmunization if mother RH negative and her baby RH positive, we need to give her RHoGAM at 28 week as prophylaxis
so then after delivery should we give her RHoGAM again immediately
or do first Rosette test then kleihauer-batke test??

When we should do these tests ?

When we should give RHoGAM immediately without testing?
Hello Kemoo:

I had a question in my Qbank related to this matter. This is how it works:

The Rosette test is a QUALITATIVE measure of fetal blood cells in the mother, therefore the result is POSITIVE or NEGATIVE

The Kleihauer-Batke is QUANTITATIVE measure of fetal blood cells in the mother.

Clinical settings:

1) You have a mother who is Rh (-) and has delivered her second baby, a beautiful female (Rh+) without complications. You administer Rhogam prophylaxis in an standard dose of 300ug
No Rosette, no Kleihauer Batke test.

2) You have a mother who is Rh(-) but had a very complicated delivery, in which you suspect feto-maternal hemorrhage.
First you do the Rosette test to check if there are fetal cells in the mother.
If this is POSITIVE: you must do Kleihauer Batke test
If this is NEGATIVE: you should administer Rhogam prophylaxis in its standard dose of 300 ug.

Now, let's think that the Rosette test is positive, you do the Kleihauer BAtke test, the result of this test will tell you the amount of blood cells that you have in the mother's circulation. With this information you administer Rhogam at a higher dose than the usual.

15 ml of fetal cells need 300 ug of Rhogam, so if the test stimates that you have 30ml of fetal blood cells, you should administer 600 ug. However the administration (I am not very sure of this) is 300 ug shots up to 5 shots. In severe cases you can administer IV Rhogam.


I hope you find this useful =)
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  #4  
Old 06-24-2011
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Hi Kemoo, I was working on my answer to your question and then Sadalssud beat me to it! I'll still post what I found. It sounds like Sadalssud confirmed my memory that the qbanks recommend not doing the rosette test for normal deliveries. You'll see below that UpToDate actually suggests doing the rosette test for all deliveries as there are not always signs of hemorrhage. When we find conflicting info like this, it usually means that it's a controversial topic and therefore CK exam will make sure the question unambiguous.

-screen for RhD antibodies in all RhD neg at first prenatal visit and again at 28 weeks gestation

-standard 300 microgram dose given at 28 wks and again postpartum (within 72 hours of delivery). This dose of immune globulin is enough to protect against maternal sensitization from as much as 15 mL red blood cells (30 mL Rh(D)-positive fetal whole blood). Approximately 1 in 1000 deliveries will be associated with excessive fetomaternal hemorrhage (greater than 15 mL red blood cells); risk factors (eg, cesarean delivery) will only identify 50 percent of these cases. Therefore, routine testing* of all women for excessive fetomaternal bleeding at the time of delivery should be performed.--this is the recommendation from UpToDate

*However, I believe the Kaplan/UW questions I had suggested that in a healthy delivery, the standard dose is given and no testing is needed, however if fetomaternal hemorrhage is suspected, perform a Rosette test (high sensitivity) (think Rosette-Red, to check for blood...)
If pos, do a Kleihauer-Betke stain to quantify (think K--to "Kuantify") hemorrhage (give 300 microgram Rhogam for every 15 mL of estimated fetal blood in maternal serum).

I suspect that a test question would make it clear if hemorrhage was present.

*Rosette test for initial evaluation, and if that is positive, a KB test. A Kleihauer-Betke test or flow cytometry is recommended to determine the percentage of fetal red blood cells in the maternal blood. The percentage of fetal red blood cells is multiplied by 50 to estimate the volume of the fetomaternal hemorrhage (50 is the factor used to represent the average maternal blood volume of 5 liters).
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  #5  
Old 06-24-2011
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Quote:
Originally Posted by healer2b View Post
Hi Kemoo, I was working on my answer to your question and then Sadalssud beat me to it!

LOL!
Sorry =)
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Old 06-24-2011
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Quote:
Originally Posted by Sadalssud View Post
LOL!
Sorry =)
No worries! I'm sure we both learned something!
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Old 06-19-2015
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Sorry to bump such an old thread... but I had been confused about the KB test, specifically when to perform it.

I had noticed in pretty much every OB question I had gotten, when given the option to either do the KB test, or just go ahead and give RhoGAM.... the answer was always give RhoGAM.

So my question is...

If you *suspect* Maternofetal hemorrhage -- eg, a traumatic automobile accident and now the mother has vaginal bleeding -- is it appropriate to FIRST give RhoGAM... and THEN work up the potential amount of fetal blood that has entered the mother via the KB test... and the REDOSE with RhoGAM if you now calculate you didn't give enough?

This is my rationale for why the answer is always usually just give RhoGAM... get it in quickly, then reassess the dose you will need?
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