Contributed by Jansen N Seheult, MB BCh BAO and Alesia Kaplan, MD
An O Rh(D)-positive term infant with intra-uterine growth restriction was delivered by elective C-section at 38 weeks to an O Rh(D)-positive G2P2 mother. The APGAR scores were 9 /10 at 1 minute and 9 /10 at 5 minutes. At birth, the baby was noted to have petechiae. Initial laboratory results confirmed severe thrombocytopenia (nadir 10,000/無). The hematocrit, white cell (WBC) and red cell (RBC) counts were normal to low. Disseminated intravascular coagulation (DIC) was considered in the differential and antibiotics were initiated; however, the DIC workup showed normal fibrinogen levels, and cultures and viral testing for TORCH infections were negative.
Prenatal screening of the mother included confirmation of rubella immunity and testing for HIV, Hep B, syphilis, and group B strep were negative. The mother's past medical history was negative for any episodes of thrombocytopenia, and her platelet count at delivery was normal at 210,000/無. The mother's red cell antibody screen was negative.
Head CT from the second day of life showed multiple intraparenchymal hemorrhages (also present on the MRI performed the following week). Trends in RBC, WBC, hemoglobin levels and platelet counts are shown in Figures 2 and 3. Random donor platelets and intravenous immunoglobulin (IVIg) were administered as indicated in Figure 3. The threshold for platelet transfusion was 50,000/無 due to the intracranial hemorrhage. The neonate had good increments with random donor platelets for the first three days after birth (highest platelet count of ~ 360,000/無) but failed to respond to 3 doses of random donor platelets a week later. The team was unable to maintain a platelet count above 50,000/無 so further diagnostic and treatment options were explored. Samples from from the mother and father were sent out to a reference laboratory for evaluation of anti-human leukocyte antigen (HLA) and anti-human platelet antigen (HPA) antibodies and for platelet genotyping, and the team simultaneously initiated the process for maternal platelet donation.