IVIG Indication in Neonatal Thrombocytopenia
IVIG at 1 g/kg as a single dose is indicated for neonates with immune-mediated thrombocytopenia when platelet counts fall below 20 × 10⁹/L or when clinical hemorrhage is present, regardless of platelet count. 1
Primary Indications for IVIG
Neonatal ITP (from Maternal ITP)
Treatment thresholds:
- Platelet count < 20 × 10⁹/L without bleeding 1
- Any clinical hemorrhage regardless of platelet count 1
Dosing regimen:
- Single dose of IVIG 1 g/kg (may repeat if necessary) 1
- Produces rapid response in more than 80% of cases 2
- Acts more rapidly than corticosteroids 2
Life-Threatening Hemorrhage
For organ- or life-threatening bleeding:
- Administer platelet transfusion combined with IVIG 1
- Add high-dose corticosteroids 1
- Goal is to elevate platelet count to hemostatic levels immediately 1
Clinical Context and Monitoring
Post-delivery assessment:
- Obtain cord blood platelet count by clean venepuncture (not by draining from cord) 1
- Avoid intramuscular injections (including vitamin K) until platelet count is known 1
- Platelet counts typically nadir between days 2-5 after birth 1
Imaging requirement:
- Perform transcranial ultrasonography on neonates with platelet counts < 50 × 10⁹/L at delivery 1
Duration and Follow-Up
Long-term considerations:
- Neonatal thrombocytopenia secondary to maternal ITP may last for months 1
- Occasionally requires a second dose of IVIG at 4-6 weeks after birth 1
- Requires long-term monitoring 1
Critical Differential: Neonatal Alloimmune Thrombocytopenia (NAIT)
When to suspect NAIT instead of maternal ITP:
- Severe thrombocytopenia with clinical hemorrhage in neonates is rare from maternal ITP 1
- When present, exclude neonatal alloimmune thrombocytopenia by laboratory testing 1
IVIG efficacy differs by etiology:
- In NAIT, IVIG has no apparent effect on platelet count 3, 4
- Matched platelet transfusion is the treatment of choice for NAIT 3, 4
- Random-donor platelets alone are effective first-line treatment for unexpected severe NAIT 4
Common Pitfalls to Avoid
Do not confuse thrombocytosis with thrombocytopenia:
- Thrombocytosis (elevated platelets) requires no treatment and has no thrombotic risk in neonates 5, 6
- Thrombocytopenia (low platelets) may require IVIG as outlined above 1
- These are opposite conditions requiring opposite management approaches 5, 6
Do not use IVIG for:
- Reactive thrombocytosis (elevated platelets) 5, 6
- Neonatal alloimmune thrombocytopenia as monotherapy (use matched platelets instead) 3, 4
Do not attempt fetal platelet assessment: