Subject(s)
Fetal Diseases/diagnosis , Pregnancy Trimester, First , Prenatal Diagnosis/methods , Rh Isoimmunization/diagnosis , Rho(D) Immune Globulin/genetics , Adult , Blood Grouping and Crossmatching/methods , Blood Grouping and Crossmatching/standards , Female , Genotype , Humans , Pregnancy , Pregnancy Trimester, First/blood , Prenatal Diagnosis/standards , Rho(D) Immune Globulin/bloodABSTRACT
BACKGROUND: Hemolytic disease of the fetus and newborn (HDN) is caused primarily by feto-maternal RhD incompatibility. Although all RhD negative pregnant women undergo routine antenatal RhD prophylaxis at 28 weeks of gestation, and following delivery if the newborn is RhD positive, HDN has not been eradicated. Here, we investigated fetal Rhesus D (RHD) genotype in maternal plasma during the first trimester of pregnancy in our area. METHODS: Plasma samples were obtained from 111 RhD negative pregnant women, between 9 and 13 weeks of gestation. DNA from maternal plasma containing cell-free fetal DNA (cffDNA) was analyzed by quantitative PCR (qPCR) to detect RHD exons 5 and 7. A beta-globin (HBB) sequence was quantified to estimate total DNA concentration. qPCR results were compared with newborn RhD determined in cord blood serum. The influence of several gestational parameters on DNA concentration was also analyzed. RESULTS: The specificity and sensitivity of the assay was 93% and 100%, respectively, with 97% diagnostic accuracy. Cell-free DNA concentrations during the first trimester of pregnancy were not affected by the gestational parameters studied (free-beta fraction of human chorionic gonadotropin and pregnancy-associated plasma protein A concentrations, fetal sex, materno-fetal ABO blood group incompatibility, maternal weight and gestational age). CONCLUSIONS: Non-invasive fetal RHD genotyping during the first trimester of pregnancy can be determined with a high specificity, thus representing a valuable tool for improving the management of RhD negative pregnant women. As a high percentage of pregnant women participate in the routine first trimester combined screening program for aneuploidies, the fetal RHD study could be of immediate implementation, since the same blood collection could be used.
Subject(s)
Fetal Diseases/genetics , Rh-Hr Blood-Group System/genetics , Exons , Female , Fetal Diseases/blood , Genotype , Gestational Age , Humans , Maternal-Fetal Exchange , Polymerase Chain Reaction , Pregnancy , Pregnancy Trimester, First , Prenatal Diagnosis , Rh-Hr Blood-Group System/blood , Sensitivity and Specificity , beta-Globins/geneticsABSTRACT
BACKGROUND: Neonatal infection remains a major diagnostic problem because of non-specific clinical signs and symptoms, as well as low sensitivity and specificity of routine laboratory tests. C-reactive protein (CRP), white blood cell count, absolute neutrophil count and immature/total neutrophil ratio are the most widely used tests in the diagnosis of sepsis and provide useful information, but none of these has demonstrated to be reliable in detecting all septic infants. Procalcitonin (PCT) has been suggested as a potentially useful laboratory test performed in umbilical cord blood when perinatal bacterial sepsis is under investigation. METHODS: In this study, the reference interval for umbilical cord blood serum PCT was established for the first time by Time-Resolved Amplified Cryptate Emission (TRACE) technology. RESULTS: The reference interval for PCT in umbilical cord blood serum ranged from 0.04 to 0.43 microg/L in 168 non-infected newborn infants (95% CI 0.02-0.06 and 0.35-0.60 microg/L, respectively). Cord blood serum PCT correctly classified one infected patient out of 90 newborn infants at risk of vertically transmitted sepsis and identified another neonate as a potentially infected patient despite having negative blood cultures. However, cord blood CRP misclassified 21 out of the 90 patients as infected neonates. CONCLUSIONS: Cord blood PCT measured by TRACE is a potentially more useful early marker of neonatal sepsis than cord blood CRP.
