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
AIM: The aim of this study was to evaluate the passage of fetal erythrocytes into the maternal circulation after invasive obstetric procedures, using the Kleihauer-Betke test, flow cytometry and α-fetoprotein concentration in maternal blood. MATERIAL AND METHODS: This was a prospective descriptive study on patients who underwent: amniocentesis, cordocentesis, chorionic villus sample, amniotic infusion, bladder drainage and ventricular-amniotic shunt to investigate the karyotype; treatment for hydrocephalus, oligohydramnios, obstructive uropathy and polyhydramnios; and investigation of lung maturity. Maternal blood samples were collected before and 60 min after the invasive obstetric procedure in order to evaluate the passage of fetal erythrocytes using the Kleihauer-Betke test, flow cytometry and α-fetoprotein concentration. RESULTS: In total, 43 invasive obstetric procedures were performed. The procedures performed were: 27 cases of amniocentesis (62.7%), seven cases of cordocentesis (16.2%), four chorionic villus samples (9.4%), two amniotic infusions (4.7%), two ventricular-amniotic shunts and one bladder drainage (2.3%). After one case of cordocentesis with two puncture attempts via the placenta, a significant increase in fetal erythrocytes was detected using the three methods. After another cordocentesis with one puncture via the placenta, a significant increase in fetal erythrocytes was detected using flow cytometry and α-fetoprotein concentration, but not through the Kleihauer-Betke test. The other 41 samples did not show any significant increase in fetal erythrocytes in the maternal blood. CONCLUSION: Invasive obstetric procedures performed during prenatal care are safe when performed by experienced professionals with the proper technique, with minimal chance of passage of fetal erythrocytes into the maternal compartment.