Diagnosis and management of Rh alloimmunization

Abstract

Objective: To assess the current problem of alloimmunization in a tertiary referral center in Croatia. The results obtained were compared to data published worldwide.

Methods: Retrospective case analysis included women with Rhesus (Rh) alloimmunization treated in our department from January 1997 to January 2003. Data of interest included the incidence, prevention, diagnosis and treatment, with the final point being perinatal mortality and morbidity.

Results: 23 pregnant women with alloimmunization were identified. The incidence was 0.138% of deliveries in the same time period. The median gestational age at diagnosis/referral was 22 (range 9-37) weeks. Anti-D antigen, alone or in combination with the other antigens, was responsible for more than 90% of the alloimmunization cases included. A defined protocol for prevention of Rh D immunization after previous delivery was not followed properly in 9/19 cases. A particular problem was prophylaxis after previous pregnancy termination (TOP), whereby only 1/14 woman received adequate prophylaxis and only after 2 of 5 TOPs. Regarding fetal treatment, 9/23 women had a total of 24 intrauterine intravascular blood transfusions. Overall, perinatal mortality was 13%, and the median gestational age at delivery was 34 (range 31-40) weeks. In all there were 31 fetal exchange transfusions after delivery performed in 14/20 newborns.

Conclusion: Despite precise diagnostic criteria and modern therapeutic options, alloimmunization remains a problem in Croatia. It is still related with a high perinatal mortality and morbidity. The main problem is inadequate prevention.