General Obstetrics and Gynecology Fetus-Placenta-NewbornNeonatal alloimmune thrombocytopenia: Antenatal management☆,☆☆
Section snippets
Methods
Eighteen pregnancies in 16 women at risk for neonatal alloimmune thrombocytopenia and receiving antenatal care at the University of Utah Medical Center or the LDS Hospital from 1992 through 1997 were included. Subjects were identified because they had previous pregnancies complicated by neonatal alloimmune thrombocytopenia. All previously affected neonates had ecchymoses or petechiae. Three had intracranial hemorrhage, and 1 bled excessively with circumcision.
The diagnosis of neonatal
Results
Six (33%) of 18 fetuses had normal platelet counts, were not treated, and were delivered uneventfully. These included 2 cases wherein the pertinent antigen was not identified, 2 pregnancies in the patient with HPA-3a sensitization, and 2 cases of HPA-1a isoimmunization with an antigen-negative fetus. An additional pregnancy with HPA-1a sensitization resulted in very mild fetal thrombocytopenia (120-136,000/μL) and a normal term vaginal delivery. The father was homozygous for HPA-1a, prompting
Comment
Although the recurrence risk of neonatal alloimmune thrombocytopenia in subsequent pregnancies is reported to be 80% to 90%,2, 7, 8 more than one third of the neonates in this series were either unaffected or only minimally affected. Severe thrombocytopenia was most common in patients with HPA-1a isoimmunization, occurring in 10 (77%) of 13. In contrast, thrombocytopenia did not recur in 2 cases of HPA-3a sensitization and in 2 of 3 patients wherein the specific antigen incompatibility could
Acknowledgements
We thank Alyssa Hamblin for her assistance in preparing this manuscript.
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Cited by (0)
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Supported in part by the Benning Fund.
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Reprint requests: Robert M. Silver, MD, University of Utah School of Medicine, Department of Obstetrics and Gynecology, Room 2B200, 50 North Medical Dr, Salt Lake City, UT 84132.