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?
A
Schedule an amniocentesis for amniotic fluid bilirubin at 16 weeks
B
Repeat titer in 4 weeks
C
Repeat titer in 28 weeks
D
Schedule PUBS to determine fetal hematocrit at 20 weeks