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Antenatal testing

Published on 03 September 2021

We use antenatal testing to determine the ABO and D group of the mother and to check for atypical red cell antibodies.

Tests are required at booking and at 28 weeks.

Routine tests aren't needed at other times unless a transfusion is required or an antibody needs further investigation.

Group and screen

  • Group and screen is used to determine the ABO and Rh type.
  • RhD negative women will need anti-D prophylaxis unless they are already sensitised to the D-antigen.

Antibody identification

  • Used when the antibody screen is positive to identify if the antibody (or antibodies) could cause hemolytic disease of the fetus and newborn (HDFN).

Antibody titration or quantitation

  • Anti-D and anti-C are quantified, all other antibodies are titrated.

Maternal test for fetomaternal haemorrhage

  • Kleihauer (acid elution) or flow cytometry

Cord blood group

  • For anti‐D immunoglobulin prophylaxis in RhD negative women.
  • For red cell antigen testing and direct antiglobulin test (DAT) in women with red cell antibodies.

Find out more about: Scottish National Guidance: Pregnant women with red cell

DNA genotyping of fetus

  • For women who have an antibody which may cause serious haemolytic disease of the fetus and newborn and the father is predicted to be heterozygote or unknown.
  • NHS Blood and Transplant: IBGRL offer non-invasive fetal genotyping for mothers with red cell antibodies.