Should Cord Blood Results Be Used As An Official Type on File with Blood Bank?

Umbilical Cord Blood Testing

Umbilical Cord Blood testing is a commonly performed procedure immediately after giving birth. It is indicated for mothers who are RhD negative as well as mothers who type as O. Some physicians may request Cord Blood testing on mother's of other types but it is not common unless Fetal/Maternal type mismatch related hemolysis is suspected (ex. Baby is A, Mom is B)

In some Blood Banks/Transfusion Centers, Umbilical Cord Blood is a "for diagnostic purposes only" sample type. Considering this, the Blood Type that is traditionally done as part of a Cord Blood Workup is not treated as an official Blood Type on file for the patient. Per AABB Standard 5.14.1 two blood types on file are required to receive Type Specific and Electronically Crossmatched PRBCs. As such, even if a blood type was performed on the Cord Blood, two separate heelsticks would need to be performed as part of the pretransfusion process to meet this standard. 

I can't find any indication from AABB that Cord Blood is unacceptable for use as an official type. It's likely up to the individual medical director to make the call. I've heard of institutions even performing Type and Screens from the Cord Blood. Why so against using Cord Blood for pretransfusion needs?

Outside of the US according to the National Pathology Accreditation Advisory Council for Australia in their Requirements for Transfusion / Laboratory Practice they outright say "Cord blood must not be used for pretransfusion testing." in C8.3(i)

In the United States, Christiana Care out of Wilmington, DE DOES allow for cord blood specimens to be used per according to their specimen acceptability.

"For neonates, a properly labeled EDTA cord blood or pediatric venous specimen is required"

Cord Blood Contamination during Collection

I think the answer generally lies within the higher possibility of Cord Blood contamination with maternal Red Blood Cells. During the collection of Umbilical Cord blood immediately after birth, it is possible that maternal blood surrounding the cord/placenta may inadvertently and unknowingly drip into the sample tube. Enough contamination could affect the outcome of the Rh interpretation or the entire Blood Type determination. There is also possibility that during birth a retroplacental hemorrhage occurs, which may allow maternal blood to enter the space of the umbilical cord circulation. These sources of potential area are nearly completely removed simply by performing a heelstick. 

I have seen this situation arise previously. The Blood Bank received a Cord Blood and typed O pos (D4 typing: 2+ positive). The baby was subsequently transferred to the NICU where it is commonplace to order "For Possible Transfusion" Type and Screen's on the patients being admitted. A heelstick was performed to collect the Type and Screen and was sent to Blood Bank. The heelstick specimen was typing as a perfect O negative. The Du (weak D) testing was also negative indicating a true O neg. A second heelstick was performed, and revealed O negative once again. What happened? Mom was O positive. It is extremely likely that the collection was contaminated somehow by maternal red blood cells. 

This is certainly not a common occurrence however. This study shows near perfect matches between Umbilical Cord Blood and heelstick specimens. The only divergence was between a few DAT results. The Blood Types matched 100% between samples. I think though that this simply shows that both sample types are valid for use, it doesn't rule out the chance for user error within the system, such as a nurse haphazardly drawing the Cord Blood. 

For those that do accept Cord Blood as official it seems to actually have its benefits. There are studies that have shown if the laboratory can use Cord Blood for initial admission testing, rather than using heelsticks, the clinical outcome of the neonate seems improved. This is especially apparent for low and very low birth weight neonates. It saves from having to take what little blood might be in circulation in these neonates. It can prevent the need for excessive vasopressors and even delay or remove the need for PRBC transfusion.   

How does your Transfusion service handle this?


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