Evaluation of passage of fetal erythrocytes into maternal circulation after invasive obstetric procedures

Abstract

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 -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 60min after the invasive obstetric procedure in order to evaluate the passage of fetal erythrocytes using the Kleihauer-Betke test, flow cytometry and -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 -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.