<prompt> Two weeks later, the results of the patient;s prenatal labs come back. Her blood type is A, with an antl D antibody titer of 1:4. What Is the most appropriate next step In the management of this patient?Schedule an amniocentesis for amniotic fluid bilirubin at 16 weeksRepeat titer in 4 weeksRepeat titer in 28 weeksSchedule PUBS to determine fetal hematocrit at 20 weeks  <response>: Indirect coomb;s test If the ICT is positive it should be repeated in dilution to find the Antibody titre.The critical titre for anti D antibodies is 1:16.If the titre is less than 1:16 it may be repeated 2 weekly.It is possible to do a immunoassay for anti D antibodies.The safe level is 4IUml.This is useful only in first sensitised pregnancy TEXTBOOK OF OBSTETRICS, SHEILA BALAKRISHNAN ,Pg no:311,2nd edition 