Sir.—Intravenous gammaglobulin (IVIG) therapy has been used with success in cases of neonatal thrombocytopenia caused by transplacentally transferred maternal autoantibodies1,2 and in neonatal isoimmune thrombocytopenia.3
Recently we reported a persistent increase in platelet count after 0.4 g/kg per day of intact polyethylene glycol–treated IVIG during the first 5 days of life in a neonate with immune thrombocytopenia, passively acquired from his mother.4
In another case, IVIG treatment was without benefit in a neonate with passive immune thrombocytopenia. In this case, the infant's mother had mild thrombocytopenia during the pregnancy (platelet count, 70 × 109/L). Her first child was noted to have thrombocytopenia at 2 months that spontaneously resolved after 2 months.
A male infant was born at term (gestational age, 39 weeks) by vaginal delivery to a woman with a normal pregnancy. His birth weight was 3740 g; Apgar scores were 9 at