<prompt> Which of the following is a non-invasive test used to diagnose fetal Rh genotype in Rh D alloimmunization?Cell free fetal DNAChorionic villus samplingAmniocentesisMiddle cerebral aery peak systolic velocity  <response>: Fetal Rh D genotype assessment from maternal blood offers several potential benefits. Administration of anti-D immune globulin to an Rh D-negative pregnant woman carrying an Rh D-negative fetus can be eliminated.In the setting of Rh D alloimmunization, early identification of an Rh D-negative fetus can avoid unnecessary amniocentesis andor serial fetal middle cerebral aery Doppler assessment. Rh D genotype evaluation using cell-free fetal DNA is done using real-time PCR to target multiple exons of the RHD geneRef: Williams Obstetrics; 25th edition 