Establishment and validation of haematological reference intervals for newborns aged 5 to 28 days in Nanjing, China

Background: China lacks a standard for reference intervals (RIs) of complete blood cell (CBC) counts in newborns. This study aimed to determine local haematological RIs for newborns. Methods: This prospective study was conducted from January 2020 to December 2020 in Nanjing Maternity and Child Health Care Hospital. We collected capillary blood specimens from 497 healthy newborns aged 5-28 days. We calculated the RIs as nonparametric 2.5th to 97.5th percentiles and 90% confidence intervals following the EP28-A3c guideline. We validated the RIs in another 20 specimens from healthy newborns. Results: The RIs for the 18 CBC parameters were: white blood cell count 7.17-15.69 x 109/L; monocytes# 0.52-1.66 x 109/L; Mono% 5.7-14.1; eosinophils# 0.16-1.08 x 109/L; Eos% 1.5-8.9; Lymphocytes# 4.04-8.08 x 109/L; Lymph% 40.1-67.8; Neutrophils# 1.59-6.41 x 109/L; Neut% 18.1-46.7; Basophils# 0.00-0.04 x 109/L; Baso% 0.0-0.4; red blood cell count 3.38-5.89 x 1012/L; haemoglobin (Hb) 116-198 g/L; Hematocrit % 35.2-61.2; mean corpuscular Hb (MCH) 30.9-36.3 pg/L; MCH concentration 310-341 g/L; mean corpuscular volume 94.5-112.2 fL; and platelets 210-610 x 109/L. The RIs had a conformity rate of 90%-100% in the validation specimens. Conclusion: We established region-specific RIs for CBC parameters in healthy newborns to help diagnose haematological disease in neonates.

Automated summary

This study aimed to establish local reference intervals (RIs) for complete blood cell (CBC) counts in newborns. Capillary blood specimens were collected from 497 healthy newborns, and the RIs for 18 CBC parameters were calculated following the guideline. The conformity rate of the RIs in the validation specimens was 90%-100%. Conclusion: Region-specific RIs for CBC parameters in healthy newborns were established to aid in the diagnosis of hematological diseases in neonates.