Incidence, demographic characteristics, and geographic distribution of sickle cell trait and sickle cell anemia births in Michigan, 1997-2014.

Background: This study describes the incidence, demographic characteristics, and geographic distribution of sickle cell anemia (SCA) and sickle cell trait births in Michigan.

Methods: Michigan newborn screening records and birth certificates (1997-2014) were used to identify sickle cell trait and SCA births, as well as demographic characteristics and mother's residential address. Incidence was calculated overall and by county.

Results: During the study period, there were 592 SCA births and 33,404 sickle cell trait births in Michigan. The majority of SCA (86.3%) and trait (80.2%) cases were among children who were black. Children with SCA were born in 23% of Michigan counties; children with trait were born in 93%.

Conclusion: Compared to SCA, sickle cell trait births occur at 50-fold greater incidence and have a substantially expanded geographic distribution. Further research is necessary to understand the most appropriate and impactful use of resources to increase the proportion of families and adults that are aware of their sickle cell trait status.