Blood Group: Duffy

Common:  34% of caucasians, and 22% of blacks, are Fya- and at risk for developing anti-Fya. The duffy null phenotype is very rare in caucasians but found in 68% of blacks who would be at risk for developing anti-Fya. [5]

Causes HDN: Yes

Critical Titer: 1:16


HDN due to anti-Fya is uncommon and usually mild. In a study of 68 affected pregnancies, only 3 were severely anemic, and 2 of those required IUTs [2]. In another article, 3 of 18 Fya positive infants required phototherapy, while only one required an exchange transfusion [4]. This stands in contrast to a French infant who required 4 IUTs and an exchange transfusion after birth [7] and a literature review saying that 32% of anti-Fya cases required an exchange transfusion [8]. Additional cases of anti-Fya requiring IUTs have been recorded [9].

Anti-Fya can have a negative direct coombs test in the infant but baby still be affected [1].

As of 2007, Ohio State University concluded that anti-Fya has “the potential to lead to significant fetal hemolysis. Management guidelines developed for D sensitization are appropriate for pregnancies complicated by anti-Fy(a) alloimmunization.” [6]


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