Guideline for prevention of RhD alloimmunization in RhD negative women

Summary

Events following which anti-D immunoglobulin should be given to all RhD negative women with no anti-D antibodies: First trimester indications (50 μg) - termination of pregnancy, spontaneous abortion followed by instrumentation, ectopic pregnancy, chorionic villus sampling, partial molar pregnancy; Second and third trimester indications (100 μg) – amniocentesis, cordocentesis, other invasive prenatal diagnostic or therapeutic procedures, spontaneous or induced abortion, intrauterine fetal death, attempt at external cephalic version of a breech presentation, abdominal trauma, obstetric haemorrhage; Antenatal prophylaxis at 28th weeks of gestation (250 μg); Delivery of an RhD positive infant * (100 μg); Minimal dose: before 20 weeks gestation - 50 μg (250 IU), after 20 weeks gestation ** - 100 μg (500 IU); Timing: as soon as possible, but no later than 72 hours after the event. In cases where prevention of RhD alloimmunization is not performed within 72 hours of a potentially sensitising event, it is still reasonable to administer anti-D immunoglobulin (IgG anti-D) within 13 days, and in special cases, administration is still recommended up to a maximum interval of 28 days postpartum.; FMH (fetomaternal haemorrhage) - If the amount of fetal erythrocytes which entered the maternal circulation is quantitatively determined, administration of 10 μg IgG anti-D per 0.5 ml of fetal erythrocytes or 1 ml of whole blood is indicated.

*also if the RhD type of the infant has not been determined or is in doubt, **in conjunction with a test to assess the volume of any fetomaternal hemorrhage.