? what's your practice - regarding moms with RhIg on board and Rh-pos babe needs product

[L.C.H.]

We've had to do some finagling in a couple cases (in light of the continuing blood shortage) and are also in the process of reviewing our SOPs, and we are curious about other folks' practices with the following setting: Mom has anti-D due to RhIg at the time of delivery. Baby is Rh-positive and needs product.  Our current SOP is that we must give Rh-negative products to the baby, because of the mom's residual RhIg showing.

I've had to override this a couple times recently in order to either comply with other maternal antibodies, or to get a young-enough unit on the fly.  Am wondering if there is actually any utility in hewing to this in our SOP, since presumably baby's Rh-positive cells are already keeping any residual maternal RhIg tied up. 

Curious how others handle this scenario!  

[jayinsat]

I would be interested in knowing how many antenatal RHIG doses the mother received. While it is possible for RHIG to cross the placenta and cause HDFN, seems to be extremely rare. The probability increases with each antenatal dose. That said, I agree with you that the baby's own cells should have sequestered any residual RHIG in circulation though I probably would not change my policy. I would just document the deviations when necessary.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4877609/

[John C. Staley]

Just curious but does the baby have a positive DAT due to the RhIG?  Is the anti:D demonstrable in the baby?  

[Malcolm Needs ★]

6 minutes ago, John C. Staley said:

Just curious but does the baby have a positive DAT due to the RhIG?  Is the anti:D demonstrable in the baby?  

Yes John,  With higher dose anti-D immunoglobulin, the DAT of a D Positive baby is quite often positive.  In the UK it is now quite common to give a dose of 1, 500 IU of anti-D immunoglobulin at 28 weeks of gestation and, as a result, many babies have a positive DAT, but I have never heard of clinically significant HDFN as a result,  Physiological jaundice is also quite common in newborns, whether the mother was given anti-D immunoglobulin or not, and whether the baby is D Positive or D Negative.

[L.C.H.]

so, to answer some questions folks have asked -

this is with a negative DAT on babe (would not consider it if the DAT was positive unless really, really stuck for product)

these are usually moms who had their 28 wk dose, but then had either episode of bleeding or motor vehicle accident or other trauma, and got one additional dose (300 micrograms) of RhIg in the third trimester. Or, alternatively, moms who got their 28 wk dose but then delivered well before 40 wks.

[Neil Blumberg]

If there is detectable anti-D in the antibody screen, would usually transfuse Rh negative blood, although the risk of clinically significant hemolysis is low.  We do not know that mild hemolysis is benign, for one thing.  

As for "freshness" this turns out to be one of the things we got totally wrong. Fresher blood (<7 days say) is probably less safe for reasons unknown than blood stored 7-21 days.  Fresher blood is associated with increased infections in the recipient in randomized trials, so our approach to this in our center has turned 180 degrees. We prefer not to use <7 day old red cells, but define fresh as 7-21 days.  Randomized trial data. 

Thus in your situation I would strongly prefer 7-21 day old Rh negative red cells to giving <7 or <5 or whatever Rh positive red cells to a child with anti-D from Rh IgG.  Freshness is harmful nonsense with a long history of expert opinion that, regrettably has been proven wrong by data.

[Ensis01]

 

On 7/27/2022 at 4:51 PM, L.C.H. said:

We've had to do some finagling in a couple cases (in light of the continuing blood shortage) and are also in the process of reviewing our SOPs, and we are curious about other folks' practices with the following setting: Mom has anti-D due to RhIg at the time of delivery. Baby is Rh-positive and needs product.  Our current SOP is that we must give Rh-negative products to the baby, because of the mom's residual RhIg showing.

I've had to override this a couple times recently in order to either comply with other maternal antibodies, or to get a young-enough unit on the fly.  Am wondering if there is actually any utility in hewing to this in our SOP, since presumably baby's Rh-positive cells are already keeping any residual maternal RhIg tied up. 

Curious how others handle this scenario!  

If you incorporate the main exceptions to policy into your SOP; it gives techs a clear path to follow if / when time is short or it is 3am. As you indicated it is hard to get O neg little c neg units (fresh or frozen).

[applejw]

We require a type and antibody screen on the neonate and transfuse according to any demonstrating antibody. 

Rh positive infants born to mothers who received antepartum RhIG usually have positive DAT with anti-D eluted from cord red cells.  The majority of these infants don't require transfusion in my experience.

[John C. Staley]

23 hours ago, Malcolm Needs said:

Yes John,  With higher dose anti-D immunoglobulin, the DAT of a D Positive baby is quite often positive.  In the UK it is now quite common to give a dose of 1, 500 IU of anti-D immunoglobulin at 28 weeks of gestation and, as a result, many babies have a positive DAT, but I have never heard of clinically significant HDFN as a result,  Physiological jaundice is also quite common in newborns, whether the mother was given anti-D immunoglobulin or not, and whether the baby is D Positive or D Negative.

What I was trying to get at is if the DAT is negative and the antibody screen is negative why would anyone consider it necessary to provide D negative red cells.   Another thought/question just occurred to me (odd, I know), why are they transfusing the baby?  Is it due to excessive blood draws or is the a hemolytic process going on?  That would make a difference as well.

[rmilford]

On 7/28/2022 at 10:07 AM, Malcolm Needs said:

Yes John,  With higher dose anti-D immunoglobulin, the DAT of a D Positive baby is quite often positive.  In the UK it is now quite common to give a dose of 1, 500 IU of anti-D immunoglobulin at 28 weeks of gestation and, as a result, many babies have a positive DAT, but I have never heard of clinically significant HDFN as a result,  Physiological jaundice is also quite common in newborns, whether the mother was given anti-D immunoglobulin or not, and whether the baby is D Positive or D Negative.

Is it your facility's policy to perform an eluate on cord blood when baby is Rh-positive and mom is Rh-negative with a passive anti-D due to RhIG? Or do you only do cord blood elution when mom has a "real" alloantibody? Just wondering about policies at other health systems. Thank you!

[Malcolm Needs ★]

16 hours ago, rmilford said:

Is it your facility's policy to perform an eluate on cord blood when baby is Rh-positive and mom is Rh-negative with a passive anti-D due to RhIG? Or do you only do cord blood elution when mom has a "real" alloantibody? Just wondering about policies at other health systems. Thank you!

We would rarely perform an eluate on the baby's red cells unless there are clinical (as opposed to laboratory) signs of HDFN.  In other words, an elution is not considered to be a "reflex test", just because the baby has a positive DAT.

[Bet'naSBB]

On 9/27/2022 at 8:18 AM, Malcolm Needs said:

We would rarely perform an eluate on the baby's red cells unless there are clinical (as opposed to laboratory) signs of HDFN.  In other words, an elution is not considered to be a "reflex test", just because the baby has a positive DAT.

For your facility in the UK - this may be common practice and I can only speak for OUR facility - but we have to do eluates on ALL our pos cord DAT's......  

We didn't have a Labor and Delivery unit for many many years - so I can't say this is being done "because it's always been done this way" this time... Our L&D opened up maybe 4-5 years ago.

[Ensis01]

58 minutes ago, Bet&#x27;naSBB said:

For your facility in the UK - this may be common practice and I can only speak for OUR facility - but we have to do eluates on ALL our pos cord DAT's......  

We didn't have a Labor and Delivery unit for many many years - so I can't say this is being done "because it's always been done this way" this time... Our L&D opened up maybe 4-5 years ago.

Have you ever found anything unexpected and clinically significant?