Management of Neonatal Isoimmune Thrombocytopenia (ICT)
For newborns with ICT, immediately administer IVIG 1 g/kg as a single dose for platelet counts <20,000/μL or with clinical hemorrhage, combined with urgent transcranial ultrasonography and avoidance of all intramuscular injections until platelet recovery. 1
Immediate Assessment and Monitoring
Initial Evaluation
- Obtain cord blood platelet count by clean venepuncture of a cord vessel (not by draining blood from the cord) immediately after delivery 1
- Perform urgent transcranial ultrasonography for all neonates with platelet counts <50 × 10⁹/L to detect intracranial hemorrhage 1, 2
- Avoid all intramuscular injections, including vitamin K, until the platelet count is known and improved 1, 2
Serial Monitoring Protocol
- Monitor platelet counts closely as they typically nadir between days 2-5 after birth 1, 2
- Perform serial platelet counts every 12-24 hours during the acute phase 3
- Continue clinical observation for bleeding manifestations throughout the nadir period 1
Treatment Algorithm
For Severe Thrombocytopenia (Platelet Count <20 × 10⁹/L) or Active Bleeding
- Administer IVIG 1 g/kg as a single dose immediately 1, 2
- Repeat IVIG dosing if necessary based on platelet response 1
- For life-threatening hemorrhage, combine platelet transfusion with IVIG 1
- Platelet transfusion should be compatible (antigen-negative) platelets when available; random platelets can be used initially to gain time until matched platelets are available 4
For Moderate Thrombocytopenia (Platelet Count 20-50 × 10⁹/L)
- IVIG 1 g/kg may be administered for clinical hemorrhage or mucosal bleeding 1
- Close clinical and hematologic observation is required 1
- Transcranial ultrasonography remains mandatory 1
For Mild Thrombocytopenia (Platelet Count >50 × 10⁹/L)
- Clinical observation without immediate treatment is appropriate for asymptomatic infants 1
- Continue monitoring as platelet counts may still decline to nadir 1
Diagnostic Confirmation
Laboratory Testing
- Perform HPA genotyping from mother, neonate, and father to identify platelet antigen incompatibility 2
- Obtain maternal serum alloantibody testing using two different serological methods 2
- Crossmatch with paternal platelets can detect alloantibodies to low-frequency antigens 2
- Exclude neonatal alloimmune thrombocytopenia when severe thrombocytopenia and clinical hemorrhage are present, as this requires different management 1
Long-Term Management Considerations
Duration of Thrombocytopenia
- Neonatal thrombocytopenia secondary to maternal ITP may persist for months and requires long-term monitoring 1, 3
- Consider repeat IVIG at 4-6 weeks after birth if thrombocytopenia persists 1, 3
- Close hematologic follow-up for minimum 5-7 days is essential 3
Response Patterns
- IVIG produces rapid platelet response in most cases within 1-2 days 5, 6
- Cases secondary to maternal ITP may have transient platelet elevations requiring repeat dosing 6
- Isoimmune thrombocytopenia cases typically show sustained platelet increases after IVIG 6
Critical Pitfalls to Avoid
- Never delay IVIG administration while waiting for compatible platelets in severe thrombocytopenia with bleeding 1, 4
- Do not administer intramuscular vitamin K before confirming adequate platelet count due to hematoma risk 1, 2
- Avoid invasive procedures including fetal scalp electrodes, scalp blood sampling, ventouse delivery, and rotational forceps during delivery 1
- Do not assume maternal platelet count, antibody levels, or splenectomy history predict neonatal severity - these are unreliable predictors 1
Special Clinical Scenarios
Coexisting Coagulopathy
- If coagulopathy is present (prolonged PT/PTT), administer fresh frozen plasma 10-15 mL/kg concurrently with platelet transfusion 3
- Repeat coagulation studies 2-4 hours after FFP administration 3
- Target platelet count >50,000/μL for hemostatic safety when coagulopathy is present 3