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Immunoglobulin (Prophylaxis) Pregnancy: Used in pregnancy — standard of care in RhD-negative women

Anti-D Immunoglobulin

Brand names: D-Gam, Rhophylac

Adult dose

Dose: Routine antenatal prophylaxis: 1500 units at 28 weeks (or 500 units at 28 and 34 weeks). Sensitising event: 250 units IM (≤20 weeks gestation); 500 units IM (>20 weeks). Postnatal: 500 units IM within 72h of delivery (if infant Rh-positive).
Route: IM injection (or slow IV for some products)
Frequency: As indicated by gestational age and sensitising events
Max: 1500 units per dose (antenatal); higher if large FMH
For RhD-negative women to prevent rhesus alloimmunisation. Kleihauer test after significant haemorrhage — if large FMH, additional anti-D may be needed. Anti-D given within 72h of sensitising event.

Paediatric dose

Route: N/A
Frequency: N/A
Max: Not applicable in paediatrics
Not applicable in paediatric patients

Dose adjustments

Renal

No dose adjustment required

Hepatic

No dose adjustment required

Clinical pearls

  • 72-hour window: anti-D ideally within 72h of sensitising event — still beneficial up to 9 days but efficacy reduced
  • Kleihauer-Betke test: performed after any significant antepartum or intrapartum haemorrhage to quantify FMH — determines if additional anti-D is needed (>4 mL FMH)
  • Sensitising events requiring anti-D: amniocentesis, CVS, external cephalic version, abdominal trauma, antepartum haemorrhage, miscarriage (>12 weeks or surgical management at any stage)
  • Check maternal blood group and antibody screen at booking and 28 weeks — if already sensitised, anti-D is futile

Contraindications

  • RhD-positive women
  • Previous sensitisation (anti-D antibodies already present)
  • IgA deficiency with anti-IgA antibodies (IV route risk)

Side effects

  • Injection site pain
  • Fever and chills (rare)
  • Anaphylaxis (very rare)
  • Haemolysis (if given to RhD-positive person in error)

Interactions

  • Live vaccines — delay for 3 months after anti-D immunoglobulin administration (may impair immune response to live vaccines)

Monitoring

  • Maternal blood group confirmation
  • Antibody screen (before administration)
  • Kleihauer test after large haemorrhage
  • Gestational age at time of sensitising event

Reference: BNFc; BNF; NICE NG25; BCSH Guidelines Anti-D Administration; RCOG Green-top 22. Verify against your local formulary and the latest BNF before prescribing.

Related

Curated clinical cross-links plus same-class fallbacks.

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