Trends in Management of Rhesus Alloimmunization Over Two Decades From a Tertiary Care Referral Center in India.

Introduction: Hemolytic disease of the fetus and newborn (HDFN) is a serious complication in pregnancy and still remains a cause of perinatal mortality, in developing countries. Antibodies to other red blood cell antigens, leading to hemolysis, are being recognized. The aim of the study is to report the outcomes in women undergoing intrauterine transfusions (IUT) for fetal anemia due to rhesus alloimmunization over the last two decades, over 3 time periods from 2002 to 2021 and to report the prevalence of minor antibodies at our center and their effect on perinatal and neonatal outcomes.

Material and methods: A retrospective record review was conducted across two decades between 2002 and 2021 over 3 time periods 2002-2007, 2011-2014, and 2015-2021. The procedures and outcomes of the first two time periods from the same center have been previously reported 7,8. For the third time period, the data were collected from hospital records of maternal and fetal medicine unit of our hospital.

Results: The entire data were divided into three time periods. These do not define watertight compartments of change in management protocols but have evolved over the years with different teams and operators. The number of transfusions has remained almost steady throughout these years; however, the percentage being referred with hydrops has decreased. Across the various time periods, a total of 311 women received 882 transfusions. The gestational age range for performing IUTs varied from 18 weeks to 34.5. The majority of the transfusions were performed between 26 and 29 weeks across the time periods. The complication rates have steadily come down over the two decades from 8.57 per procedure to 2.3 per procedure. The POG at delivery gradually increased from 31 to 32 + 6 weeks (39.5%) to between 35 and 36 + 6. The survival rates have remained high with up to 95% survival in the non-hydropic fetuses and 90% in hydropic fetuses. Anti-D antibody was most often combined with anti-C, anti-M or anti-E. In neonates of anti-D and minor antibodies group, the requirement of phototherapy and exchange transfusion was more although it was not significantly different from only anti-D group. The presence of other antibodies in addition to anti-D can be clinically significant, because these combinations reportedly are more frequently associated with therapeutic interventions for the newborn, especially anti-D plus anti-C.

Conclusion: HDFN still remains a significant problem requiring early surveillance and timely intervention. Although the survival following intervention is quite favorable, it requires intensive management with a robust support from the blood bank. Prevention strategies must be reviewed to reduce the burden of the disease.