Do any Blood Banks allow  phenotyping of pregnant patients?  Is there a timeframe defined during a pregnancy that accepts this practice? Some Laboratories phenotype and accept only negatives or strong positive reactions as conclusive. 

What does your blood bank do?

We allow it, unless there is a mixed-field reaction with any of the antisera (except of course, a Lewis type, as these change drastically with pregnancy).

Thank you for the fast response Malcolm Needs!  Is there any literature or publication that I can refer to?  Can't find this specifically in AABB.

I'll have a look at my books, but, I have to warn you that it is my wife's birthday tomorrow, and we are going away for a couple of days to celebrate, and so it will be a few days before I can so do.

On 10/6/2017 at 2:09 PM, lab217 said:

Do any Blood Banks allow  phenotyping of pregnant patients?  Is there a timeframe defined during a pregnancy that accepts this practice? Some Laboratories phenotype and accept only negatives or strong positive reactions as conclusive. 

What does your blood bank do?

I'm assuming....yes, that gets me into trouble all the time......that you're worried about antigen suppression in pregnant women?

Antisera licensed in the USA should have been tested extensively with samples from such patients. If they were unable to correctly phenotype samples from pregnant women, it's unlikely that they would have been approved. As Malcolm points out, the only real troublemakers are the Lewis antigens.

The only thing that would give me pause in phenotyping in late pregnancy would be the mixed-field reactions mentioned by Malcolm which could be the result of a fetal / maternal bleed.

We type pregnant women as well.  If, there was evidence of a fetal/maternal bleed, we would treat as we would post transfusion (not that it has happened here before!)

s

I've had a look at my books, and I can't see any references that say you should NOT phenotype during pregnancy.

This strongly suggests to me that there is no reason why a phenotype should not be performed during pregnancy (otherwise I am certain that it would have been mentioned, and that a reference would have been given).  Therefore, I go back to what I said earlier, that the phenotype is okay, unless there is a mixed-field reaction seen.  If a mixed-field reaction is seen, I would worry more about the health of the foetus than I would about the maternal typing, as, for a mixed-field to be seen, either the foetus has had a massive bleed, or has had a chronic bleed over a long period of the pregnancy.

29 minutes ago, Malcolm Needs said:

If a mixed-field reaction is seen, I would worry more about the health of the foetus than I would about the maternal typing, as, for a mixed-field to be seen, either the foetus has had a massive bleed, or has had a chronic bleed over a long period of the pregnancy.

Very good point. One could argue that ALL pregnant women should be phenotyped specifically to look for mixed fields.

The only problem with that idea exlimey is that one would only type the person once, and so you would have to be pretty lucky to coincide the typing with the foetal bleed, particularly in the case of an acute, massive bleed.

17 hours ago, Malcolm Needs said:

The only problem with that idea exlimey is that one would only type the person once, and so you would have to be pretty lucky to coincide the typing with the foetal bleed, particularly in the case of an acute, massive bleed.

Yeah, I know. I was just being silly, pointing out that sometimes what sounds like a reasonable idea is often impractical and mostly useless.

Proposed new policy: Type them once every week for the duration.