NICE guidance - use of routine antenatal anti-D ( antiD ) prophylaxis for RhD-negative women

Summary features of NICE guidance:

• routine antenatal anti-D prophylaxis (RAADP) is recommended as a treatment option for all pregnant women who are rhesus D (RhD) negative and who are not known to be sensitised to the RhD antigen
• when a decision has been made to give RAADP, the preparation with the lowest associated cost should be used. This cost should take into account the lowest acquisition cost available locally and costs associated with administration

Notes:

• sensitisation can happen at any time during pregnancy - however most common in the third trimester and during childbirth
  • sensitisation can follow events in pregnancy known to be associated with feto-maternal haemorrhage (FMH) - during pregnancy small amounts of fetal blood can enter the maternal circulation
    • events associated with FMH include medical interventions (chorionic villus sampling, amniocentesis or external cephalic version), terminations, late miscarriages, antepartum haemorrhage and abdominal trauma. It can also occur in the absence of an observed potentially sensitising event
    • risk of sensitisation is affected by the ABO blood type of the fetus, with a lower risk if it is incompatible with the mother’s ABO type. Sensitisation depends on the volume of fetal blood entering the mother’s circulation and the magnitude of the mother’s immune response
    • risk of sensitisation is greatest in the first pregnancy and decreases with each subsequent pregnancy. Once sensitisation has occurred it is irreversible
    • risk of sensitisation can be reduced by administering anti-D immunoglobulin to women in situations in which FMH is likely (after delivery, miscarriage, abortion, invasive procedures or abdominal trauma)
      • in addition, anti-D immunoglobulin can be administered routinely in the third trimester as prophylaxis against small amounts of FMH that can occur in the absence of observable sensitising events. This is known as routine antenatal anti-D prophylaxis (RAADP). The use of anti-D immunoglobulin for RAADP is in addition to the administration of anti-D immunoglobulin following potentially sensitising events, and its use in either indication is not affected by prior use in the other
  • RAADP can be given as two doses of anti-D immunoglobulin of 500 IU (one at 28 weeks and one at 34 weeks gestation), as two doses of anti-D immunoglobulin of 1000-1650 IU (one at 28 weeks and one at 34 weeks gestation), or as a single dose of 1500 IU either at 28 weeks or between 28 and 30 weeks gestation

Reference:

• (1) NICE (August 2008). Guidance on the use of routine antenatal anti-D prophylaxis for RhD-negative women. www.nice.org.uk