RESUMO
BACKGROUND: Several factors like altitude, age, sex, pregnancy, socioeconomic status, life style and race influence hematological reference interval (RIs), which are critical to support clinical decisions and to interpret laboratory data in research. Currently there are no well-established RIs for cord blood hematological parameters of newborns in Ethiopia. This study aims to generate RIs for umbilical cord blood hematological parameters of newborns from Addis Ababa, Ethiopia. METHOD: A cross-sectional study was conducted from January 1 to March 31, 2019 on healthy, term newborns (37-42 weeks) with normal birth weight born to apparently healthy pregnant mothers who had met the eligibility criteria. From 139 newborns, 2-3ml cord blood was immediately collected from the clumped cord using EDTA tube. The samples were analyzed using Sysmex KX 21 hematology analyzer. Data was entered and the 2.5th and 97.5th percentiles (upper and lower reference limit) were determined using non parametric method by SPSS version 23. The non-parametric independent Mann-Whitney U test (Wilcoxon rank-sum test) was used to compare the distribution of the parameters between genders, modes of deliveries and gestational age. P value less than 0.05 was considered to declare statistical significance. RESULT: The median values and 95 % reference interval for umbilical cord blood hematological parameters of newborns were as follows: WBC = 12.4 [6.6-19.4] x109/L, RBC = 4.51 [3.55-5.52] x1012/L, HGB = 15.8 [12.4-19.7] g/dL, HCT = 45.9[37.9-56.3]%, MCV = 102.1[83.9-111.6] fL, MCH = 35.3 [29.4-39.1] pg, MCHC = 34.3 [32.3-37.4] %, PLT = 236 [146-438] x109/L, LYM = 37.5 [16.6-63.0] %, MXD = 7.9[1.7-15.8] %, NEU = 53.7[30.3-78.4] %, RDW = 15.6[12.0-19.0]%, PDW = 11.0[9.1-15.7]% and MPV = 9.4[8.1-11.8] fL. The current study found no significant difference between genders, except RDW (P = 0.01), and gestational age group, but there was significant difference for WBC (p = 0.007), RBC (p = 0.018) and Absolute NEU (p = 0.001) by delivery type where newborns delivered through caesarean section had lower values for these three parameters compared to those with spontaneous delivery. CONCLUSIONS: hematological reference intervals in cord blood were established for the first time from healthy newborns of Addis Ababa and its surrounding. The values are applicable for newborns from this area. Larger study throughout the country is warranted.