Guidance for Prenatal, Postnatal and Neonatal Immunohematology Testing in Canada: Consensus Recommendations from a Modified Delphi Process.

OBJECTIVES: Blood Group, antibody screen, fetal maternal hemorrhage tests and Rh(D) immunoglobulin (RhIG) administration are interventions during pregnancy that aid in the prevention of hemolytic disease of the fetus and newborn (HDFN). The timing, frequency, and nature of testing vary across centres due to limited data to inform standards development. Using Delphi methodology, this study aimed to establish guidance for Canadian practice related to prenatal, postnatal and neonatal immunohematologic testing, and RhIG administration, to reduce risk and improve diagnosis of HDFN.

METHODS: A national, multidisciplinary Delphi panel rated their agreement with potential guidance statements related to prenatal, postnatal and neonatal immunohematology testing on a 5-point Likert scale during iterative rounds of voting. After each round, responses were analyzed and statements were re-sent to the panel for further ratings until consensus was achieved, defined as Cronbach's α >0.95 or a maximum of 3 voting rounds. At the conclusion of the Delphi process, statements rated ≥4/5 were included.

RESULTS: In total, 46 experts voted on 49 proposed statements. Consensus was achieved after 3 survey rounds (Cronbach's α = 0.94), with a 100% response rate throughout. Overall, 44 statements reached consensus. Statements focused on prenatal immunohematology testing (N = 21 statements), maternal-fetal hemorrhage testing and RhIG administration during pregnancy (N = 15), and testing of neonates for surveillance of hyperbilirubinemia secondary to hemolytic disease of the newborn (N = 8).

CONCLUSIONS: This Canadian consensus guidance aims to optimize the surveillance of pregnancies at risk of HDFN and the dosing and timing of RhIG administration. It provides actionable recommendations to harmonize practice and support safe, timely, and cost-effective care.