Erratum: 14 Years of Polish Experience in Non-Invasive Prenatal Blood Group Diagnosis

<b><i>Background:</i></b> Blood cell antigens may cause maternal alloimmunization leading to fetal/newborn disorders. Non-invasive prenatal diagnostics (NIPD) of the blood group permits the determination of feto-maternal incompatibility. <b><i>Aim: </i></b>To evaluate 14 years of blood group NIPD at the Institute of Hematology and Transfusion Medicine (IHTM) in Warsaw. <b><i>Methods: </i></b>Plasma DNA from 536 RhD-negative, 24 Rhc-negative, 26 RhE-negative, 43 K-negative, and 42 HPA-1a-negative pregnant women was examined by real-time PCR to detect <i>RHD, RHCE*c, RHCE*E</i>, <i>RHCE*C,</i><i>KEL*01</i> and <i>HPA*1A, </i>respectively. We tested for <i>CCR5</i>, <i>SRY</i> or bi-allelic polymorphisms and quantified the total or fetal DNA. <b><i>Results:</i></b> The results of fetal antigen status prediction by NIPD in all but one case (false-positive result of <i>KEL*01</i>) were correct taking neonate serology as a reference. It was confirmed that all negative results of NIPD contained fetal DNA except for four cases where there was no difference between the parents' polymorphisms. <b><i>Conclusions:</i></b> A fetal genotype compatible with the mother was determined in 25% of all pregnancies tested at the IHTM for the fetal blood group. These cases were not at risk of disease, so it was possible to avoid invasive procedures.