Sensitivity of Fetal RhD Screening for Safe Guidance of Targeted Anti-D Immunoglobulin Prophylaxis: Prospective Cohort Study of a Nationwide Programme in the Netherlands

摘要

The risk ofmaternal alloimmunization due to RhD incompatibility has decreased with use of antenatal and postnatal anti-D immunoglobulin prophylaxis. The discovery of cell-free fetal (cff) DNA in maternal plasma during pregnancy and the feasibility of fetal RhD testing using this source of DNA make it possible to determine fetal RhD type and to restrict the use of antenatal anti-D immunoglobulin to only those RhD-negative women carrying an RhD-positive fetus. Variable and low amount of fetal DNA present in maternal plasma and the genetic variation of RHD alleles in the fetus or mother complicate such noninvasive testing. This study was done to evaluate the efficacy of noninvasive fetal RHD testing in week 27 of pregnancy to restrict use of antenatal and postnatal anti-D immunoglobulin use to RhD-negative women carrying an RhD-positive fetus.