Newborn Screening for Sickle Cell Disease: Effect on Mortality

Abstract

Newborn screening for sickle cell disease has been recommended as a method of decreasing patient mortality. However, its effectiveness in accomplishing this has not been reliably measured. To help determine the effectiveness, 10 years of experience in newborn screening have been summarized. The effects of early patient enrollment in a comprehensive treatment program on long-term morbidity and mortality are reported. From 1975 to 1985, 84,663 newborns were screened regardless of race or ethnic background. Hb Bait's was present in 5%, hemoglobin AS in 2.6%, and hemoglobin AC in 0.75%. Excluding Bart's, approximately 3.6% of all newborns were carriers for hemoglobinopathy. Sickle cell disease occurred in 1:951 births (58 Hb 55, 25 Hb FSC, three Hb S-β+-thalassemia, and three Hb S-β°-thalassemia). In addition, one in every 4,233 newborns had a clinically significant thalassemia syndrome (eight Hb FE, ten Hb F only, two Hb H). Compared with other newborn screening programs in California (congenital hypothyroidism, 1:3,849; phenylketonuria, 1:22,474; galactosemia, 1:74,103), hemoglobinopathies are the most prevalent congenital disease. Eighty-one newborns with sickle cell disease were followed up for 7.2 years. Patients experienced 513 hospitalizations, including 13 episodes of sepsis with or without meningitis and ten acute sequestration crises. The overall mortality rate for patients with sickle cell anemia diagnosed in the newborn period was 1.8%. In comparison, the clinical course of 64 patients with sickle cell anemia diagnosed after 3 months of age and followed up for an average of 9.4 years was analyzed. Five of these patients died. In two of these, sickle cell anemia was diagnosed at the time of the death. Overall mortality rate in this group was 8%. In summary, the data indicate that newborn screening, when coupled with extensive follow-up and education, will significantly decrease patient mortality.