The consequences of unnecessary requesting and reporting of the direct antigloblin test in neonates

Published Date: 15th June 2021

Publication Authors: Bonney S, Pannikodu E, Samani S, McNulty J, Chunara U

Background:
BSH (British Society of Haematology) guidelines recommend that the Direct Antiglobulin Test (DAT) is only requested when clinically indicated in neonates. Prophylactic anti-D (PAD) administered routinely to Rh D Negative mothers during pregnancy can cause a positive DAT in the neonate that is not clinically relevant as PAD does not cause significant haemolysis (Dillon et al., 2011, Maayan-Metzger et al., 2001). However, it is common practice for clinicians to request 'Group and DAT' on all cord/heel prick samples that they send to the Transfusion Laboratory. Aim(s):
To analyse data on DAT testing in neonates performed by the Transfuision Laboratory Service at St Helens and Knowsley Teaching Hosptials NHS Trust (STHK) over a12 month period. The aim was to establish if the test was clinically indicated and what further intervention a positive result prompted.

Method(s):
A list of all DATs performened on neonates (< 4 months of age) by the STHK transfusion service from1st January 2020 to 31st December 2020 was retrospectively gathered. Postive DATs were further investigated to establish the impact of the positive result; clinical indication, additional blood tests, phototherapy, length of stay, folic acid administration and pardiatric consultation/review. Result(s):
During the audit period,1745 DATs were performed on neonates at STHK. Of these,10% (n=169) were postiive. In 80 of the postive cases (47%), the DAT was clinically indicated due to maternal antibodies or neonatal anaemia/jaundice. In over half of the positive DATs (53%) a clinical indication for the tests could not be found in the patients notes yet the mother was Rh D Negative and had recieved PAD during pregnancy. A vast majority of these DAT results were very weakly positive (97%). Half of the neonates with a non-clinically indicated but postive DAT recieved at least one intervention. Interventions included SBR and FBC teasting, folic acid administration, phototherapy, paediatric consult or 2 week review at a paediatirc out patient department.

Result(s):
During the audit period,1745 DATs were performed on neonates at STHK. Of these,10% (n=169) were postiive. In 80 of the postive cases (47%), the DAT was clinically indicated due to maternal antibodies or neonatal anaemia/jaundice. In over half of the positive DATs (53%) a clinical indication for the tests could not be found in the patients notes yet the mother was Rh D Negative and had recieved PAD during pregnancy. A vast majority of these DAT results were very weakly positive (97%). Half of the neonates with a non-clinically indicated but postive DAT recieved at least one intervention. Interventions included SBR and FBC teasting, folic acid administration, phototherapy, paediatric consult or 2 week review at a paediatirc out patient department.

Summary/Conclusion:
The reporting of non-clinically indicated DATs in neonates of mothers who have recieved PAD is a financial burden and leads to unnecessary interventions, such as additional venepuncture and folic acid administration in non-syptomatic neonates. Additional teaching sessions and better policies need to be introduced to reduce this practice. Laboratory staff should also be empowered to question the clinical relevance of DATs if requesters fails to provide clinical details.

 

Bonney, S; Pannikodu, E; Samani, S; Belcher, P; McNulty, J; Chunara, U. (2021). The consequences of unnecessary requesting and reporting of the direct antigloblin test in neonates. HemaSphere. 5 (Suppl 2), 647

Bonney, S; Pannikodu, E; McNulty, J et al. (2021 ). 1083 The consequences of unnecessary requesting and reporting of the direct antigloblin test in neonates . Archives of Disease in Childhood. 106 (Suppl 1), A220

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