Rho(D) immune globulin testing

[HWalker]

Hi all

Someone ask me today why we do a ABO/RH, antibody screen, & DAT on every workup for Rho(D) immune globulin? I said I thought it was a regulation but I think that’s wrong (actually I was thinking ‘that’s how we’ve always done’). I’m referring to pregnant women specifically.

Of course on first time patients, but what about 28 wk doses.

I hope I’m making myself clear.

Can someone give me their thoughts on it or what they do in their lab?

Hank USA

Thanks for any input

:confused:

[Malcolm Needs ☆]

Hi all

Someone ask me today why we do a ABO/RH, antibody screen, & DAT on every workup for Rho(D) immune globulin? I said I thought it was a regulation but I think that’s wrong (actually I was thinking ‘that’s how we’ve always done’). I’m referring to pregnant women specifically.

Of course on first time patients, but what about 28 wk doses.

I hope I’m making myself clear.

Can someone give me their thoughts on it or what they do in their lab?

Hank USA

Thanks for any input

:confused:

At 28 weeks, you have to make sure that there are no other clinically significant antibodies present and, as much as you possibly can (which is virtually impossible, if the antibody is weak) that there is no immune anti-D present.

Any antibody formed after 28 weeks is unlikely to cause clinically significant HDN (although there is always the odd outlyer).

:)

[John C. Staley]

Initial testing during pregnancy was the full ABO/Rh and Antibody Screen, the 28 week workup was just the antibody screen, at delivery, just Rh confrimation, that's of course, if we had the previous testing on record.

I have discovered over the years that inertia is the most powerful force in the universe. "We have always done it that way" is often impossible to over come.

:bonk:

[adiescast]

We do the full type and screen at 28 weeks. We do not perform a DAT on the mother. At delivery for the RhIg workup we confirm the ABO/Rh and perform a fetal bleed screen if the baby is Rh positive. Otherwise we don't do anything on the mother unless she needs blood (or could need blood).

[Malcolm Needs ☆]

We do the full type and screen at 28 weeks. We do not perform a DAT on the mother. At delivery for the RhIg workup we confirm the ABO/Rh and perform a fetal bleed screen if the baby is Rh positive. Otherwise we don't do anything on the mother unless she needs blood (or could need blood).

Sorry, I meant to say that we don't do a DAT either.

[LAURAA80]

At 28 weeks, since the patient isn't in-house, we only do the testing that is ordered. Some doctors order type and screen, others prefer just a type. The rhogam is not discpensed from Blood Bank, but from pharmacy. Upon admission to deliver, we do another type and screen. Post delivery, we do a type and screen as well as a fetal screen.

[HWalker]

Thank you all for the excellent feed back!

Malcolm Needs, I realize the importance of the antibody screen to monitor the Mom for atypical antibodies during the pregnancy. But I can’t figure out why we do the DAT @ 28 wks or after delivery, if RhoGAM is indicated. It was set up by the person before me and I’ve never questioned it……..till now.

John C. Staley, what you do or did makes a lot of sense to me. What makes the most sense is, “I have discovered over the years that inertia is the most powerful force in the universe. â€We have always done it that way" is often impossible to over come.

However, sometimes ‘the way we’ve always done it’ IS the best way.

Adiescast, what would do if the mother came in spotting at 11 or 30 weeks and you already knew she was a RhIg candidate? Would you repeat the ABO/Rh.

Thanks again

:D:D

[adiescast]

Thank you all for the excellent feed back!

Adiescast, what would do if the mother came in spotting at 11 or 30 weeks and you already knew she was a RhIg candidate? Would you repeat the ABO/Rh.

Thanks again

:D:D

We probably would repeat it. I am not sure how much spotting she has to do before they decide she needs more RhIg after the 28 week dose. That decision has always been made by the clinician here. At 11 weeks, they might not even involve the blood bank (we don't dispense RhIg) if they already had a type on the woman.

[Deny Morlino]

Hank,

We perform the same testing as adiescast at the same intervals. A few years ago a process was developed in blood bank at the request of our pathologist. If the mother is <13 weeks gestation we perform ABO, rh, and antibody screen on mothers presenting with vaginal bleeding. If between 13 and 28 weeks gestation we perform ABO, rh, Ab screen and a fetal bleed screen. After 28 weeks the assumption is made that RhIg has been administered and ABO, rh, and fetalscreen are performed. The AB screen and fetalscreen performed from 13-28 weeks is because the volume of fetal red cells is enough to sensitize the mother, but we have not "routinely" given the 28 week prophylactic RhIg injection. The ED (most likely place for presentation with vaginal bleeding for us) is aware of the policy of ABO / rh must be checked upon each admission per regs. Oh, we have control of the RhIg here. Not sure why the DAT is in place at your facility. Any ideas yet?

[HWalker]

I have have no idea why we do it. We're going to review the whole procedure and I'm sure that will be .

Thanks

[John C. Staley]

Thank you all for the excellent feed back!

However, sometimes ‘the way we’ve always done it’ IS the best way.

Thanks again

:D:D

....but you can not know that unless you question and challenge the status quo. It might still be the best way but unless you can identify why it is you should not simply accept it at face value because we have always done it that way.

[Malcolm Needs ☆]

There speaks a true scientist.

:):)