Are antibody screens required at delivery in obstetrics patients who had a negative antibody screen at 28 weeks?

When RhIG is administered at 28 weeks, all screens are positive in our experience. We do not have an option for a mini-screen using solid phase.

At least one obstetrician wants all of these extensively worked up, "in case the RhIG did not work".

Thank you in advance for taking your time to comment.

As there is no bullet-proof system for determining whether anti-D detected at delivery is due to passive or active immunization, we discontinued antibody screens as part of our Postpartum Rh Immune Globlulin Protocol. Has the physician indicated what he would do if "the RHIG did not work"?

At both my prior and current workplaces we quit doing antibody screens on postnatal RhIG workups.  Whatever the answer, the treatment was the same (give RhG) so what value was the test?  If the baby had a pos DAT and turned yellow then we might find a 4+ anti-D in the mom but it never happened.  The AABB perinatal guidelines say to do an Ab screen at this point only for pretransfusion testing.

Dansket and Mabel,

Thank you both. The decision to discontinue antibody screens as part of our postpartum workup is what we are looking at, for the same reasons you mentioned.  It simply does not seem to make any sense to do them under the circumstances I outlined.  And, I do not think the physician thought it through, even after much encouragement to do so.

We do type and screens on all Moms when admitted to L-D. If pos due to RHIG we do a mini-panel.(We use gel).That way if something goes wrong and an emergent C-section is needed or there is a lot of bleeding we are "good to go"  We do have a high risk obstetrical practice.

I have had a real non responder to RhIg.  We use the Extend II panel for the Echo which rules out everything since there's just the one + D cell.  I get at  least once a month an Rh= Mom with another antibody.  So yes while you are going to give another Rhig anyway, you get more information for the Mom and subsequent pregnancies by working up the alleged passive Anti D.

We dropped antibody screens on post natal samples for RhIg workup many years ago.  All OB patient's get ABO/Rh on admission.  Infant's of Rh neg mothers get ABO/Rh and DAT.  Any time the infant is DAT pos and ABO compatible with mother or anytime DAT is greater than than expected for ABO incompatibility (greater than 2+) we would perform antibody screen on mother.

Under the UK Guidelines, there is no requirement to perform a post-partum antibody screen on the mother, and no requirement to perform a DAT on the baby if the mother had no antibodies during her pregnancy (or in the past), and the mother was given routine anti-D immunoglobulin prophylaxis during her pregnancy.

We also do a type and screen on all OB patients on admission, so that we are prepared for any unexpected emergencies. We do a minipanel in gel for patients whose screen is positive and are known to have received prophylactic RhIG.   But the post partum workup (when RhIG is indicated) does not include a repeat screen. 

We do type and screens on all OB admissions as well, for potential transfusion needs.

Thank you to everyone! I appreciate your detailed responses. Have a great day.

We do types and screens on OB patients on admission and get information about RhIg prophylaxis from the nursing staff if the patient is Rh neg with a positive antibody screen. If the answer is yes, we do not do any further work-up and if the patient needs red cells, we do a Coombs crossmatch. Only if the Coombs crossmatch is incompatible, do we go back and investigate what other antibodies might be present in the mom's plasma.

But here's another question. If a woman has a preadmit appointment prior to a scheduled C-Section, do you ascertain whether or not she got prophylactic RhIg? We have had 2 cases this week where we had a terrible time getting this question answered. As in, it took hours for the doctor's office to call us back. It turned out that both of these women had allo-anti-D. Which brings me to my 2nd question. If you discover that a pregnant woman (about to deliver) or recently delivered has allo-anti-D, what do you do next? Titer, even though you have no baseline?

In both cases, we opted not to titer but to evaluate the infant upon delivery.

This week we have had an OB that has a 4+ Anti-D at AHG(gel). Saline titer was 1 and AHG titer was 4. We had pathologist speak to doctor and he said she had amnio performed, so we assumed she had rhogam. We called her Dr.'s office to obtain date and they have no record of her having an amino done or having rhogam. When we asked patient; she said she didn't know. My dilemma is whether to result this as passive or allo-immunized Anti-D. Ultimately it does not matter b/c patient will receive rh negative blood anyway but just curious what you guys think...

This week we have had an OB that has a 4+ Anti-D at AHG(gel). Saline titer was 1 and AHG titer was 4. We had pathologist speak to doctor and he said she had amnio performed, so we assumed she had rhogam. We called her Dr.'s office to obtain date and they have no record of her having an amino done or having rhogam. When we asked patient; she said she didn't know. My dilemma is whether to result this as passive or allo-immunized Anti-D. Ultimately it does not matter b/c patient will receive rh negative blood anyway but just curious what you guys think...

 

A 4+ reaction will never be due to Rhogam, only 2+ or less. Any of our ladies showing >2+ reactivity get sent for quantification.

Something doesn't add up if you're getting a 4+ but only a titre of 1:4 in IAT

A 4+ reaction will never be due to Rhogam, only 2+ or less. Any of our ladies showing >2+ reactivity get sent for quantification.

Au contraire, mon ami.  (Don't know where the French came from!  Must be the international flavor of this site.) We have had 4+ reactions from RhIG when the injection was very recent, ie. in the last few weeks.  We have some ED physicians who think that when a patient comes in three times in a week with vaginal bleeding, they need a shot each time.  This will pop the titer high enough that the screen will be 4+, but what doesn't add up for me is the part about the patient having an amnio, but neither the Dr's office nor the patient knows for sure.  Who said she had an amnio?  Does the patient remember an amnio but not if she got a shot?  And why doesn't the Dr's office have any records?  Very interesting!

First and foremost how does one not remember having an amnio? Second those administering the RhIG should be giving these moms the patient ID card that all of the products on the market have within the product insert.

 

Next for your ER docs that keep administering RhIG for bleeding they should discuss with the Chief of OB and the Blood Bank Medical Director the protocol set in place by ACOG for multiple bleeding episodes.

What method are you using? If you are using solid phase you can get 4+ reactions with low titer anti-Ds that are due to RhoGAM.

First and foremost how does one not remember having an amnio? Second those administering the RhIG should be giving these moms the patient ID card that all of the products on the market have within the product insert.

 

Next for your ER docs that keep administering RhIG for bleeding they should discuss with the Chief of OB and the Blood Bank Medical Director the protocol set in place by ACOG for multiple bleeding episodes.

Agreed, Kimster, but our ED medical director thinks he is God (who would have guessed?) and I think the docs often don't even bother to read the chart or they wouldn't keep ordering Rh types either.  We do have one physician who actually called the patient's OB and determined she had RhIG in the office the week before and so she didn't need any more.  Small steps, very small steps...

At both my prior and current workplaces we quit doing antibody screens on postnatal RhIG workups.  Whatever the answer, the treatment was the same (give RhG) so what value was the test?  If the baby had a pos DAT and turned yellow then we might find a 4+ anti-D in the mom but it never happened.  The AABB perinatal guidelines say to do an Ab screen at this point only for pretransfusion testing.

DITTO!

We do the workup/tests ONLY if clinically indicated, i.e. no 'routine orders', must be ordered by the pediatrician for a reason.

We do perform 'Rh-Only' on the cord blood of Rh-neg mothers because we need that test result to determine if she needs Rh-Immune Globulin.

I see 4+ reactions frequently, when we use solid phase and the patient received it recently.

OMG! You can't remember having amnio??? I had one with my last pregnancy. They can deaden the skin so the shot doesn't hurt but they can't deaden the uterus. It is one big old muscle. Of course they told me that fact just before punching it thru. It was like getting punched with a big nail from a nail gun. Let me say it wasn't pleasant! It has been over twenty years ago and I still remember.  I almost cried watching my little son trying to swim away from the intrusion into his space.

 

I don't believe that she doesn't remember. I always suspect fraud. We had a mom that gave birth and then gave birth again 3 months later. ??? It also happened that her blood type was different the second time which is the reason we really started looking and investigating. ?? It turns out the first mom gave birth and the medicaid card worked so well she let her friend who was also pregnant use her card when it was time for her to give birth. (!?!?)