RESUMO
Screening of fetomaternal hemorrhage (FMH) is essential in management of fetomaternal antigen incompatibilities of blood. The objective in this study was to evaluate the ability of automatic blood analyzer (ABA) to screen FMH, also comparing this method with flow cytometry (FCM). The contents of fetal red blood cells and fetal hemoglobin were evaluated by FCM and ABA, respectively, using both blood samples of male adults laced with umbilical cord blood diluted at 1/10, 1/100, 1/1,000, and 1/10,000, or blood from puerperal women collected within 48 hours following delivery. FCM had better performance (area under curve, AUC = 0.8723) than ABA (AUC = 0.6569) in detecting fetal blood laced with blood from male adults. At a critical level of 0.5%, ABA indicated that 27.5% of puerperal women would have FMH while FCM did not detect FMH. Our results showed that ABA overestimates FMH and disagrees with FCM on indicating puerperal women with FMH. ABA is inadequate for being used to screen for or to measure FMH.
Assuntos
Antígenos/sangue , Incompatibilidade de Grupos Sanguíneos/sangue , Transfusão Feto-Materna/sangue , Testes Hematológicos/métodos , Adolescente , Adulto , Antígenos/imunologia , Incompatibilidade de Grupos Sanguíneos/patologia , Feminino , Sangue Fetal/imunologia , Hemoglobina Fetal/imunologia , Transfusão Feto-Materna/imunologia , Transfusão Feto-Materna/patologia , Citometria de Fluxo , Humanos , Masculino , Pessoa de Meia-Idade , Período Pós-Parto , Gravidez , Sistema do Grupo Sanguíneo Rh-Hr , Adulto JovemRESUMO
The authors describe the histological features of the placenta in a typical case of twin-to-twin transfusion, with particular attention focused on the stereologic aspects. Villi from the anemic placental portion were slightly edematous, with small and inconspicuous vessels. The stereologic characteristics of this portion were nearer values of normal placentas. The plethoric region appears as a postmature organ, with a very thin trophoblast layer and numerous vasculo-syncytial membranes. The most dramatic alterations of this region were mainly related to the foetal capillary. According to the stereologic results, the consecutive circulatory alterations would facilitate the maternal-fetal exchanges in the plethoric placental territory, thus justifying the greater development of this twin.