We have a patient 13 weeks pregnant. Type and screen done. Patient is D neg, with "anti D" id'ed. There is no record of patient getting RhIG and patient denies getting Rhig. Antibody was tiltered with a less than 1 result obtained.

I have never seen a "real" anti D that was not detected in the titration. Have others seen this?

'Fraid so. If you just happen to "catch" someone, just as they are developing anti-D (or any other antibody specificity, come to that), the antibody can be extremely weak.

As usual, Malcolm is correct.

We have a lady who had Anti-E a few years ago. Then the last time we saw her the antibody was not demonstrable. Now she is pregnant, and the weak Anti-E is back with a titer of only 1:1.

Donna

As noted above, timing is everything. I've also seen a couple of patients with known anti: D which dropped below detectable levels. Always keep in mind that rare is not the same as never and never is a word best forgotten when dealing with biological systems.

Just out of curiosity, how many opportunities has you patient had to be exposed to D positive RBCs?

:juggle:

I saw a patient once that kept coming in for *** bleeding but left the ED against medical advice the first time and didn't get RhIG. The next time, I pulled out a very weak anti-D. Later in the same pregnancy she had a high enough titer she had to deliver at a bigger hospital that had a NICU. She had a couple of previous kids and was living in a homeless shelter so I always wondered if she left the first time because she knew she was paying by the hour for the ED and knew she couldn't afford it since she had no insurance. It all ended up costing a whole lot more since she became a high risk delivery.

Oh the joys of insurance based medicine!

As noted above, timing is everything. I've also seen a couple of patients with known anti: D which dropped below detectable levels. Always keep in mind that rare is not the same as never and never is a word best forgotten when dealing with biological systems.

Just out of curiosity, how many opportunities has you patient had to be exposed to D positive RBCs?

That was going to be my question. Part of our Antibody Workup is several questions regarding previous pregnancies and / or transfusions. If they do not know, we ask if they have ever been an inpatient at another hospital and give their Blood Bank a call. It is amazing how some folks have little knowledge of the details of their medical history.

Patient history is an art form to some extent. I can't tell you how many times the patient who has never "received RhIG" will mention getting a "vitamin shot" at the OB clinic.

We had a similar situation - a pregnant female with an Anti-D and a 1 for a titer ... After an exhausting search (calling clinicians and several outreach clinics), she was indeed correct when she told us she had never received RhIg. It was hard for us all to believe but it was true! I agree - I think it is all about timing