Rh-incompatible hemolytic disease of the newborn in Hefei

Background: Anti-D antibody is not the common cause of Rh-isoimmunization in Chinese neonatal jaundice. Recent change in national population policy has followed by an increase in Rh-isoimmunization related hemolytic disease of the newborn (HDN). Unfortunately, regional status of Rh-HDN is unavailable. We hypothesize that Rh-HDN in our region is most commonly due to anti-E antibody.

Aim: To investigate the prevalence of hemolytic disease of the newborn due to Rh-isoimmunization in Hefei City.

Methods: Retrospective review of data obtained from Children's Hospital of Anhui and Hefei Blood Center between January 2017 and June 2019. Status of minor blood group antibody was studied in the corresponding mothers.

Results: Totally 4138 newborns with HDN admitted during the study period and 116 (2.8%) received blood exchange transfusion (BET). Eighteen newborns (0.43%) with proven Rh-incompatible HDN were identified. All were not the first-born baby. Thirteen mothers were RhD (+) (72%) and five were RhD (-). The distribution of Rh-related antibodies in mothers was ten anti-E (55%), five anti-D (27%), and for one anti-C, anti-c, and anti-E/c (6%) each. Thirteen (72.2%) were qualified for BET, relative risk for BET was 28.9 as compared to other types of HDN, but only 10 received due to parenteral refusal. All (100%) RhD related HDN received BET which is not significantly different from RhE related HDN (81.8%).

Conclusion: As expected, all Rh-incompatible HDN newborns were not the first-born. Contrary to the Caucasian population, anti-D induced HDN is not the most common etiology. In our region, anti-E (11/18, 61%) is the most common cause of Rh-HDN.