Significant medical progress has been made in the past 50 years in the prevention of hemolytic disease of the fetus and newborn (HDFN), reducing incidence around the world.
Before advances in prevention, early detection, and treatment, HDFN was known to cause fetal death in 1% of all pregnancies. Today, the incidence of HDFN has been reduced to 0.1%, thanks to preventative measures like prenatal screening and fetal monitoring treatments like the use of anti-D immunoglobulin in Rh-negative pregnant women.
However, HDFN is still prevalent, and it’s more common in some geographical areas and demographics around the world than others.
HDFN in different ethnic groups
HDFN can be caused by Rh or ABO incompatibility between the mother and fetus. ABO incompatibility is the less severe of the two. While still a common cause of HDFN, its severity is generally lower. Other rare types of incompatibility include antibodies against antigens (e.g., anti-K, anti-M) of other blood groups.
Medical researchers establishing global database to study HDFN
The Rh-negative blood type is more common in some ethnic groups and races than others. For example, the National Institutes of Health (NIH) found that in the U.S., it is more often found in white races (15%) than in African Americans (5%-8%), and is even less predominant in Native Americans and Asians (1%-2%).
Similarly, HDFN has been shown to affect ethnic groups differently. According to a study, HDFN has a greater prevalence in whites (15%-16%), followed by African Americans (8%), Africans (4%), Eurasians (2.4%), and Asians (<1%).
HDFN around the world
In more developed, higher-income countries, the incidence of HDFN has been dramatically reduced in recent decades. However, in countries lacking the resources to implement the recommended prevention and screening measures, prevalence remains high. Epidemiological differences in the population, different medical protocols and the availability or lack of resources all contribute to higher mortality and morbidity in less industrialized countries.
This has been demonstrated in the findings of a variety of studies around the world.
A study in the United States published in May 2023 in AJOG Global Reports based on data from 1996 to 2010 found the HDFN live birth prevalence to be 1,696 cases per 100,000 births, with the majority of cases occurring in white women. Whereas in Europe, live birth prevalence was estimated to be 817 to 840 cases per 100,000 births.
In the Asian population, incompatibility with the anti-M antigen is a much more common cause of HDFN than HDFN due to anti-D and anti-K antigens. In China, anti-D-related HDFN is still linked to negative outcomes and death in fetuses and newborns.
In Africa, another study demonstrated that antibodies against Kell blood types were more prevalent than Rh antibodies, leading to recommendations for routine antibody screening on blood samples.Anti-D-related HDFN is the most common cause of HDFN in India, so prenatal screening focuses on Rh-negative women with no routine screening for ABO HDFN, and the estimated risk of ABO HDFN is 2.9%.
