Antenatal management of severe feto-maternal alloimmune thrombocytopenia:
HLA incompatibility may affect responses to fetal platelet transfusions
MF Murphy, P Metcalfe, AH Waters, J Ord, H Hambley and K Nicolaides
Department of Haematology, St Bartholomew's Hospital and Medical College,
London, UK.
In feto-maternal alloimmune thrombocytopenia (FMAIT), severe hemorrhage,
particularly intracranial haemorrhage (ICH), may occur before delivery.
Management strategies to prevent ICH in high-risk pregnancies include
maternal administration of intravenous Ig with or without steroids and
fetal platelet transfusions. This report describes a patient who lost three
fetuses with ICH because of FMAIT due to anti- HPA-1a. ICH occurred earlier
in successive pregnancies (at 28, 19, and 16 weeks of gestation) despite
maternal treatment with intravenous Ig and steroids from 14 weeks of
gestation in the third pregnancy. The fourth pregnancy was managed by
administering weekly intraperitoneal injections of Ig to the fetus from 12
to 18 weeks of gestation. At 18 weeks, there was no evidence of ICH, but
the fetal platelet count was only 12 x 10(9)/L. Serial fetal platelet
transfusions were started, but there were poor responses because of immune
destruction of the transfused platelets by maternal HLA antibodies. There
were improved responses to transfusions prepared from the mother and from
HLA- compatible HPA-1a-negative donors. At 35 weeks of gestation, a normal
infant was delivered by Caesarean section after 20 platelet transfusions.
There was prolonged thrombocytopenia in the baby for 15 weeks after birth,
probably due to transfer of HPA-1a antibodies in the transfusions of
unwashed maternal platelets. The optimal management of pregnancies likely
to be severely affected by FMAIT is still evolving. Intensive management
was successful in this case, but a successful outcome cannot be guaranteed
in severely affected cases. This is the first time that HLA incompatibility
has been found to complicate fetal transfusion therapy.
Volume 81,
Issue 8,
pp. 2174-2179,
04/15/1993
Copyright © 1993 by The American Society of Hematology
