Donating blood and pregnancies

I donated blood yesterday and there was a new question on the intrusive form.
Have you had four or more pregnancies?
A quick internet search did not the reasons for the new question. Does anybody know the purpose of this new question?

With more pregnancies, you’re more likely to have developed antibodies, which could then cause adverse reactions in a recipient. There’s a condition called TRALI - Transfusion-Related Acute Lung Injury, which seems to be connected to antibodies in donor plasma, more specifically to something called HLA antibodies, which are more likely to be present in multiparous women (more than one pregnancy).

The American Red Cross is transitioning to using predominantly male donor plasma, to try and minimize the risks.

Another interesting answer/doper name combination.

There is a common suggestion that many women get pregnant and never know it because they miscarry so early so it is attributed to an early or late period. I wonder how they come up with a number like 4, if such a thing is as common as I’ve heard.

I think it depends on how late into the pregnancy she is before she miscarries, I think. The antibodies are only produced when there’s an exchange of fetal and maternal blood. Depending on the circumstances, if it’s a very early natural termination, there’s probably not too much exchange of blood. But I’m not an expert on that, it’s just a guess.

Do we have a doctor in the house??

I’m sorry, but I just had to register amusement at that username/post combination.

Dude, why do you think I chose the name? Lab rat and bio geek for life!

Doctor in the house.
A pregnancy needs to go to roughly 12 weeks for there to be enough foetal blood for the mother to be able to develop antibodies.

Women who are Rhesus negative, therefore usually don’t require antiD if they spontaneously miscarry before 12 weeks.

You’d usually know if you’d had a miscarriage or termination at 12 or more weeks.

So are they rejecting blood donations from women who’ve been pregnant at least four times, or just plasma donations?

I don’t know where gazpacho was filling out the questionnaire - I haven’t donated blood in a year, but last time I did, it was with the American Red Cross and that question wasn’t asked of me.

Either way, they (the ARC) are not currently rejecting blood donations from women who’ve had more than 4 pregnancies, as far as I’ve been informed. However, other entities also collect and process blood donations and have their own questionnaires - it’s possible that some hospital centers are rejecting all multiparous women from the donor pool, although I haven’t heard of that around here. The ARC is slowly trying to switch their plasma donor pool to an all-male pool, for the safety reasons mentioned, but they’re not there yet. Other products can be made from an average blood donation, including red cells and platelets, so even if the policy changed to male-only plasma, they wouldn’t turn those women away at the door. The red cell component has so little plasma left in it that the risks to the recipient would be negligible in the vast majority of cases.

And on that note, people, if you’re able to and willing to, please consider donating some blood soon. In the Washington/Baltimore area, the shortage is getting pretty dangerous. It’s at the point now that for some blood types, we can’t even keep a floating pool of units on the shelf, we need to call the Red Cross and beg for units on a case-by-case basis, And that scares the hell out of me.

Sorry for the public service announcement, I just felt like I had to.

Antigen, MT(ASCP)

I have no idea what they are doing with people who have had 4 or more pregnancies. The San Diego Blood bank page does not give any information on the subject.

Antigen, This was with the San Diego Blood Bank and the question is new in the last 3 months. They did not have the question the previous time I donated blood.

I donate platelets with Bloodnet, USA, and they ask if I’ve ever been pregnant, just so they know to test for that antibody thingy.

The question I’ve seen the last few times, that I didn’t remember from before (when I didn’t donate through the ARC), was one of the answers to the “Have you ever been pregnant?” questions. There are the “yes” and “No” options, but then there is a third one “Not sure”.

Huh? I mean, if an early miscarry is probably not enough to produce antigens in the mother (like mentioned above)… what is that question supposed to mean? Is it a roundabout way of asking “Have you had sex without birth control since your last period and you’re in the middle of your cycle?”?

I last donated whole blood in June at a local hospital/medical school. They asked “Have you ever Been pregnant, had an abortion or a miscarriage?”.

They started asking questions about previous pregnancies two or three years ago, IIRC. I asked what was up at the time and the nurse said something about they were collecting extra blood for a study. I guess the study proved something.

The question “Female donors: Have you been pregnant or are you pregnant now?” is also on the list, but I seem to recall it used to be only Are you pregnant now?

If you’re pregnant now, does that mean you can’t give blood, or that they advise against it?

From the San Diego Blood Bank

The page does not seem to be updated about 4 or more pregnancies.

What kind of antibodies?

If it was only, say, the ones for “foetus and mother have different blood types,” wouldn’t a mother be zero risk if her kids had the same or less-letters ABO group and she was Rh+?

I asked the nurse about the pregnancy questions when I went to give blood again. She didn’t seems like she really knew what she was talking about, but apparently it’s because when you are pregnant your body creates some form of antibodies which remain present in your plasma. If the plasma from a pregnant or post-person is given to some recipients it can cause breathing difficulties. I asked her about whether or not that cut down on the donor pool, and she just sighed and said yes.

A little googling came up with this site about Transfusion Related Acute Lung Injury (TRALI)

Sorry about the slightly-zombie thread revival.

I donated platelets and just made an appointment to donate again. About 5 minutes later the woman from the Red Cross called back to tell me that the Red Cross recently decreased the amount of pregnancies allowable to be a platelet donor. I have had three pregnancies, one live birth. My miscarriages took place after the three month mark some of you inquired about. This is the latest. I’m bummed.

Update, I donate blood regularly through a local organization. For about the past year they have been asking how many pregnancies, and have disallowed me to donate plasma only. I can still do other donations, but because of having 4 pregnancies, I cannot donate plasma. As antigen stated previously, this is due to the antibodies created when pregnant which are suspect in causing Trali in the blood recipient.

Wouldn’t the risk also depend on how many different fathers there were? If you have only one partner, and his antigens are all compatible with yours, then it won’t matter how many times he gets you pregnant. And even if he’s not a perfect match, there’s still a limited number of antigens your children could have. If you have babies by multiple men, though, you could in principle get exposed to any number of antigens.