Impact of prematurity and immigration on neonatal screening for sickle cell disease.
BACKGROUND
Others have described a relationship between hemoglobin A levels and gestational age, gender and ethnicity. However, studies are needed to determine normal cut-off points considering these factors. To address this issue we designed a study to determine the percentiles of normality of neonatal hemoglobin A levels taking these factors into account.


METHODS
This cross-sectional study involved 16,025 samples for sickle cell disease screening in the province of Alicante, Spain, which has a high immigration rate. The primary variable was hemoglobin A, and the secondary variables were gender, gestational age (preterm and full term) and maternal origin (Spain, the rest of Europe, North Africa, Sub-Saharan Africa, Latin America and Asia). Percentiles of normality (1 and 99) were obtained by origin, gender and gestational age using quantile regression models and bootstrap samples. The association between these percentiles of normality and altered levels (≥1%) of hemoglobin E was analyzed. We obtained the percentiles of normality (1 and 99) for each maternal origin, gender and gestational age.


RESULTS
Of a total of 88 possible E carriers, 65 had above-normal hemoglobin A levels (74%). The levels of normality for hemoglobin A varied greatly according to the maternal origin and gestational age.


CONCLUSIONS
With the levels of normality that we established it is possible to discard samples with unrecorded blood transfusions. Our methodology could be applied to other diseases in the neonatal screening.
Department of Pharmacology, Pediatrics and Organic Chemistry, Miguel Hernández University, San Juan de Alicante, Alicante, Spain.
Ernesto
E
Cortés-Castell
Department of Clinical Medicine, Miguel Hernández University, San Juan de Alicante, Alicante, Spain.
Antonio
http://orcid.org/0000-0002-5959-9631
A
Palazón-Bru
Department of Clinical Analysis, Alicante General University Hospital, Alicante, Alicante, Spain.
Carolina
C
Pla
Center for Advanced Research in Public Health, Generalitat Valenciana, Valencia, Valencia, Spain.
Mercedes
M
Goicoechea
Department of Nursing, University of Alicante, San Vicente del Raspeig, Alicante, Spain.
María Mercedes
MM
Rizo-Baeza
Department of Pharmacology, Pediatrics and Organic Chemistry, Miguel Hernández University, San Juan de Alicante, Alicante, Spain.
Mercedes
M
Juste
Department of Clinical Medicine, Miguel Hernández University, San Juan de Alicante, Alicante, Spain.
Vicente Francisco
VF
Gil-Guillén
D000755:Anemia, Sickle Cell / Q000175:diagnosis* / Q000453:epidemiology; D003430:Cross-Sectional Studies; D004641:Emigration and Immigration; D005260:Female; D005865:Gestational Age; D006441:Hemoglobin A; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D008297:Male; D008403:Mass Screening; D015997:Neonatal Screening; D013030:Spain / Q000453:epidemiology / Q000208:ethnology
D006441:Hemoglobin A