Haemolytic disease of the newborn

Last updated: Friday, 06, August, 2010
Key InformationAppropriate Tests

Maternal alloimmunisation to Rh or other red cell antigens, with development of clinically significant red cell antibodies causing fetal/neonatal haemolysis.

In countries with effective maternal screening and appropriate prophylaxis with Rh(D) immunoglobulin, the prevalence of Rh haemolytic disease of the newborn is greatly reduced; ABO incompatibility is now the commonest cause of haemolytic disease in developed countries.

Maternal screening

Maternal blood group, ABO and RhD blood groups and an antibody screen routinely at first antenatal visit (8-12 weeks).

  • Mother Rh(D) positive - no alloantibodies detected

Repeat blood group antibody screen at 26-28 weeks, as dictated by the clinical circumstances and the judgement of the obsterician.

  • Mother Rh(D) negative - no alloantibodies detected.

Repeat blood group antibody screen at 28, and 34 weeks. If anti-D prophylaxis is to be given, the blood must be drawn prior to the RhD-IgG being given. If RhD-IgG has already been given an earlier sensitising event, then the antibody screen must still be performed and the date of the prior administration noted on the request form1.  

Due to constraints on supply, the Australian Red Cross Blood Transfusion Service currently recommend anti-D at 28 and 34 weeks for first pregnancies in Rh negative women, as well as prophylaxis post natally and for all sensitising events in all Rh negative women without preformed antibodies (see http://www.csl.com.au  and http://www.giveblood.redcross.org.au)

  • Clinically significant alloantibodies  detected in maternal serum: see section 4.1 of the Guidelines for Blood Grouping and Antibody Screening, 3rd edition, March 2007.

Repeat blood group antibody screen (testing) at 4 week intervals until 32 weeks gestation then every 2 weeks until delivery. Further action depends on specificity, titre and quantitation (where appropriate, e.g. anti-D, anti-c) of the antibody

At risk fetus

If appropriate, serial ultrasound; amniocentesis (bilirubin - amniotic fluid); cordocentesis (cord blood - blood group, direct anti-globulin test, haemoglobin) are used to determine need for intrauterine transfusion. MCA Doppler is now considered the standard of care to measure foetal anaemia.

These pregnancies are best managed in consultation with a fetal medicine specialist, due to the unpredictable course of fetal haemolysis; delivery should be planned at an institution with facilities for exchange transfusion.

Neonatal haemolysis

Cord blood - blood group, direct antiglobulin test, haemoglobin, blood film; bilirubin.

Maternal blood - blood group and testing for alloantibodies.

If initial tests are negative, testing against the paternal red cells may be required.

Monitor infant haemoglobin, bilirubin to determine the need for exchange transfusion and for measures to reduce unconjugated bilirubin levels.

  • ABO incompatibility

As above.

Elution study may be required. Monitor haemoglobin levels to detirmine need for transfusion.

  • Rh incompatibility

Cord blood:Rhd status, including weak D.

Maternal: Rh phenotype. Red cell elution study may be required.

FMH testing (Kleihauer test) af ALL Rh negative females who deliver a Rh positive infant to asses adequate dosage of Rh-IgG.

References:

1) Guideleines for Blood Grouping & Antibody Screening in the Antenatal & Perinatal Setting. 3rd edition, March 2007. Australian and New Zealand Society of Blood Transfusion and The Royal Australian and New Zealand College of Obstericians and Gynaecologists: http://www.ranzcog.edu.au/publications/index.shtml

2) The Royal Australian and New Zealand College of Obstetricians and Gynaecologists. College Statement C-Obs 3: "Antenatal Screening Tests" November 2006

3) Antenatal Care for the Healthy Pregnant Woman, NHS and NICE October 2003: http://www.nice.org.uk/CG006