PRENATAL-DIAGNOSIS OF THE RHD FETAL BLOOD-TYPE ON AMNIOTIC-FLUID BY POLYMERASE CHAIN-REACTION

Objective: To assess the accuracy of a molecular assay for the determi nation of the fetal RhD status on amniotic fluid (AF) samples. Methods : Amplification of DNA by polymerase chain reaction of a common sequen ce of the RhD and CE genes and of a unique sequence of the RhD gene wa s performed on AF directly or after DNA extraction. Samples of AF obta ined from patients undergoing amniocentesis for standard obstetric ind ications were used for the study. Results: Amplification of DNA was su ccessful on 112 of 114 samples. One hundred four fetuses were found to be RhD positive and eight were found to be RhD negative. Serologic co nfirmation of the RhD blood type was available on 108 samples and DNA diagnosis was correct in all cases. Conclusion: Polymerase chain react ion can be used to determine accurately the fetal RhD blood type from AF samples.