To Established Hematological Reference Intervals Among Full-Term Newborn Babies at University of Gondar Comprehensive Specialized Hospital, Northwest Ethiopia: A Cross-Sectional Study

Background: Hematological reference intervals are used for medical decision tools for interpretation of numerical test results. Establishing of hematological interval among newborn babies is very important for the diagnosis of malignancy, anemia, bleeding disorders, and various infections. There is no locally established hematological reference intervals in Ethiopia. Thus the aim of this study is to established locally determined hematological reference interval among full-term newborn babies. Methods: A cross sectional study was conducted from February to May 2019 among 151 apparently healthy full-term newborn babies at Gondar University Hospital. About 3ml of cord blood was obtained for analysis of Hematological parameters and determined by using Sysmex KX-21N (Sysmex Corporation Kobe, Japan) automated analyzer. Median, 2.5 th and 97.5 th percentiles were computed. Result: Males to female’s ratio was almost equal. All hematological parameter had no statistically signicant difference between males and females. The delivery types were not inuenced its hematological values. Conclusion: Hematological reference interval was established from full-term newborn babies at University of Gondar hospital and was different from other studies in African and Europeans. Therefore, own determined reference value is very important for the clinicians to correctly diagnosis the patients at health facility levels.


Introduction
Establishing hematological reference intervals among full-term newborn babies at University of Gondar comprehensive specialized hospital, Northwest Ethiopia: a cross-sectional study Background Umbilical cord blood (UCB) is the blood remaining after in the excluding of the placenta. It is considered as biological waste products. However, it has many advantages like stem cell transplantation (rich in hematopoietic progenitor and stem cells), RH blood typing of the newborn babies, assessment of the neonatal thrombocytopenia or thrombosis, screening and diagnosis of anemia, polycythemia, bacterial sepsis and determination of hematological reference interval (RI) (1)(2)(3). The other main advantage of UCB is it minimizes blood draw from very ill newborn babies that cause increased morbidity and mortality during neonatal life. The UCB is the alternative source to eliminate unwanted repeated blood drawn for laboratory tests. The collection of UCB is safe for the patients and technically easy as compared to other blood collection sites (4).
The UCB is composed of white blood cells (WBC), red blood cells (RBC), plasma, platelets and is also rich in hematopoietic stem cells, which have immense potential to cure the malignant and genetic disorder. Therefore, establishing of hematological RI among newborn babies from UCB is very important for neonatologist for the diagnosis RBC disorders (like anemia and polycythemia), hematological malignancy, platelet disorders (like thrombosis and thrombocytopenia), autoimmune disease, certain genetic disorders problems, monitoring of the patients during in a therapeutic regimen and diagnosis of various bacterial infections (5)(6)(7). It is widely known that newborn hematological parameters are different from those of infants or adults. Therefore, separated hematological RI is mandatory for newborn babies (8).
RI is the range between values from the lower reference limit to the upper reference limits (9). They are ideally de ned on apparently healthy individuals and should be distinguished from clinical decision limits that are derived from known diseased patients. It is a distribution of numerical test results expected in a representative population of healthy individuals. It is mainly used to make medical decisions about hematological disease diagnosis, treatment & monitoring of disease prognosis of the patients (10).
According to Clinical Laboratory Standards Institute guideline, the RIs are de ned in relation to a healthy population to include the values in which 95% of apparently healthy individuals would fall and in which 2.5% of results in the lower range are out of the RI and 2.5% of values in the upper range will be out of the RI (11,12).
Hematological RIs are the most common medical decision-supporting tools used for the interpretation of numerical hematological test results. Accurate patient results interpreting within the correct RI is mandatory to minimize the patient risks from disease, increase recovery rates, and improve monitoring therapy of various hematological disorders (13). Almost 80% of physicians' medical decisions are based on information provided by laboratory reports. Therefore, locally established hematological RI among newborn babies is very important for the physician to correctly diagnosis and early treatment of the patients (14).
In Ethiopia there is no locally determined hematological RI among healthy full-term newborn babies in the country, particularly is in the study area. They used in Western and American RI. Since hematological RI is varying through age, race, ethnicity, altitude, sex, drug intake, time of sampling and socioeconomic status.
It is commonly known that newborn hematological parameters are different from those of neonates, infants or adults (8). It need locally determined RI. Due to these reason we motivate to conduct this study. The aim of this study was to establish hematological RI by using UCB of apparently healthy, full-term newborn babies at University of Gondar compressive specialized hospital.

Study Setting, design and population
An institution-based cross-sectional study was conducted from February 1 to May 30, 2019, at the gynecology and obstetrics department of University of Gondar comprehensive specialized hospital, Northwest Ethiopia. The hospital is located in Amhara region, 180 km far from Bahir Dar, the capital city of Amhara regional state and 727 km from Addis Ababa, the capital city of Ethiopia. The town located 2,133 meters' elevation above sea level. The hospital has a range of specialties including pediatrics, surgery, gynecology, psychiatry, human immunode ciency virus (HIV) care, and an outpatient clinic.
The newborn babies were selected based on the following criteria: Birth at full-term (39-42 weeks of gestation), and absence of any congenital anomalies. All selected newborn babies were physically examined at birth and found normal and apparently healthy. The premature newborn (delivered less than 37 weeks of gestation), twin newborns, the pregnancy complicated with diabetics, preeclampsia, hypertension, HIV/AIDS, chronic kidney, liver disease, malaria, anemia, and hematological malignancy were excluded from the study. On the other hand, a mother who had bleeding during pregnancy, maternal drinking of alcohol during pregnancy, cigarette smoking during pregnancy, and no antenatal care also were excluded from being sampled. A systematic random sampling technique was employed to select study participants. A total of 151 newborns babies with their respective mothers were included. Maternal hemoglobin (Hgb) values less than 11 g/dl will be excluded from the study.

Data Collection Method
Socio-demographic and clinical data collection A pre-tested structured questionnaire prepared in English and translated to the local language (Amharic) was used to obtain newborn gender, birth weight, and presence of bleeding during pregnancy, alcohol consumption habits, and cigarette smoking during pregnancy via face-to-face interviews. The presence of maternal complications like malignancy, hypertension, diabetics, tuberculosis, HIV/AIDS, chronic kidney, and liver disease were retrieved from maternal medical records with the aid of data extraction sheet.
Blood collection and laboratory analysis About 3 ml of UCB specimen were obtained from each study participants after delivery from the clamped umbilical cord. The two trend Midwifery professionals collected the cord blood sample from the clamped cord through excluding of the placenta. The collected sample was immediately poured into tri-potassium ethylene diamine tetraacetic acid (K3-EDTA) test tube and gently mixed to prevent blood clotting. In addition, 3 ml of venous blood was collected from the mother after delivery with a sterile and disposable syringe. Hematological parameters: total white cell count (WBC), differential white cell count (neutrophils, lymphocytes and mixed which contains eosinophils, monocytes. and basophiles), platelet count, red blood cell count (RBC), Hgb, hematocrit (%), mean cell volume (MCV), mean cell hemoglobin (MCH), mean cell hemoglobin concentration (MCHC), and red cell distribution width (RDW) were determined by using the using Sysmex KX-21N (Sysmex Corporation Kobe, Japan) automated hematological whole blood analyzer based on direct current principle. Three experienced laboratory technologist performs the complete blood count (CBC) by strictly adhering standard operating procedures.

Data quality control
In order to increase the reliability of data, training was given for the data collector prior to data collection. During laboratory data collection standard operating procedures were strictly followed and implemented from prior to specimen collection up to recording and interpreting of the laboratory results. After sample collection immediately dispensed to the wall of the EDTA test tube slowly and properly mixed by inverting the tube gently 8-10 times to prevent hemolysis of blood samples. Then label of the sample and the request paper with the same identi cation number in order to avoid any mix up of errors. The expired date of reagent was checked before analysis of patient samples. Daily installations and background run were done to minimize any background errors. Repeated analysis of randomly selected samples for reproducibility check (delta check) was carried out to evaluate instrument performance consistently and precisely.

Statistical analysis
The data were cleaned, edited, checked for completeness, and entered into Epi-info version 7.2.1.0. Then it was exported into SPSS version 20 for analysis. Outliers were detected by using Z score and Tukey method. Before any analysis, normal distribution of numerical data was checked using the Kolmogorov-Smirnov and Shapiro-Wilk test. Since all data are not Gaussian distributed we used non-parametric tests to determine the hematological RI as recommended as the clinical laboratory standard institutes (12). Median with interquartile range (IQR), and 95% con dence interval were computed. The 97.5th percentile and 2.5th percentiles were the upper and the lower reference limit of the study populations, respectively. Mann-Whitney U test also used to test for the mean difference of variance between gender (male versus female), and delivery type (vaginal versus cesarean section). According to the guideline of clinical laboratory standard institutes, we determine the 95% hematological RI by computing 97.5th percentile and 2.5th percentile.

Results
Sociodemographic and obstetric data of study participants A total of 151 healthy newborn babies (76 females and 75 males) were included in this study. Majority of study participant (87.4%) were born from mother came from urban residence with normal birth weight (90.1%). About 81.5% of study participants were born through spontaneous vaginal delivery route and the remaining were by cesarean sections (Table 1). The minimum vs maximum value of cord WBC, cord RBC, and cord platelet among study participants were (3.6 vs 27) x10 6 /L, (3.02 vs 5.7) x10 12 /L, (132 vs 500) x10 9 /l, respectively. As a result, summarized in Table 2

Hematological reference interval
The newborn babies hematological RI is determined based on non-parametric estimation methods. Based on the SPSS statistical analysis of newborn laboratory data did not require partition by sex groups. As clearly mentioned above Table 2 showed that all hematological value did not have a statistically signi cant difference of means among sex groups as well as the route of delivery types. According to clinical laboratory approve guideline partitioning was required when the difference between the observed means of two subclasses is statistically signi cant at the 5% probability level (9). The median and 95%

Discussion
The RI has a great role in the interpretation of hematological test results. The aim of this study was to establish hematological parameters among full-term newborn babies by using UCB specimens which are the rst time reported in Ethiopia. The present study showed that mode of delivery had no in uence of hematological parameters of the newborn babies which agrees to a study done by Fady M et al reported that there was no signi cant difference in the MCV, MCH, MCHC, RDW, lymphocytes, and monocytes (15).
However, this result is contrasting to a study done by L Glasser et al showed that mode of delivery had in uenced to hematological test values.
In the current study, there was no statistically signi cant mean difference of hematological parameters between males and females which was consistent with a study reported in Sokoto, Northern Nigeria (16) and Lagos, Nigeria (17). On the other hand, Our nding of the 95% RI of RBC values were comparable to a study reported in Nepal (18), Iran (19), and Nigeria (20) reported. The of Hgb values of this study agrees with a study reported in Saudi Arabia, however, the 95th percentiles of platelet value the present study was greater than as compared to the Saudi reported (21). The 95% RI of WBC in our study similar to the study conducted in Turkey (7.64-22.16 × 10 9 /l versus 71.90-25.44 × 10 9 /l) (22).
The lower limit WBC value of this study was lower but the MCH RI were similar to a study done in Saudi Arabia (21), Nepal (18), and Pakistan (23). The Hct value of the current study was comparable to a study conducted in Logos, Nigeria and Iran. However, the lower limit of WBC was higher than a study reported in Sagamu, Nigeria, and Iran (Table 4). This may be due to the variation in geographical location, and race or genetic factors may be contributing to the presence of this difference. The 95th percentile RI of the current study lower limit of RBC was lower than studies conducted in Saudi Arabia and Sagamu Nigeria. On the contrarily, the higher limit of 95th percentile RI of Hgb value of this study was higher than is a study was done in Logas Nigeria, Iran, Iraq and Sagamu Nigeria. The difference of Hgb value might be due to method variation, inclusion criteria of the study participants and time of cord clamping. Similarly, the higher limit of 95th percentile RI of both WBC and platelet values were higher than in the study conducted in Nepal, Pakistan, Logas Nigeria, Iran and Iraq (17-19, 23, 24).
The platelet counts of this study range from (132.7-413) x10 9 /L. Based on our nding less than 132 × 10 9 /L is thrombocytopenia and greater than 413 × 10 9 /L is thrombocytosis for newborn babies. The lower limit of platelet counts in the current study were consistent to a study reported from Mashhad, Iran (19) (131 × 10 9 /L). However, the higher limit of the current study was higher in this study done by Marwaha et al (142 × 10 9 /L) (25). The major limitation of this study was nucleated RBC is not corrected when total WBC was counted at the time of analysis.

Conclusion
Hematological RI was established from full-term newborn babies at University of Gondar compressive specialized hospital Northwest Ethiopia were different from African and Europeans. Each Hematological RI was no statistically signi cant among male and female newborn babies. The current nding of RI is very helpful for the physicians to accurately diagnose and monitoring of therapies of the patients.

Declarations
Ethical approval and consent to participate The research was conducted after obtaining an ethical clearance letter from the School of Biomedical and Laboratory Science Ethical Review Committee. A permission letter was obtained from the University of Gondar compressive specialized hospital. Written informed consent was obtained from each selected mother after explaining the aim of the study with the potential adverse effects during sample collection. The results of the study participants were used without personal identi ers and only used for research purpose.

Consent for publication
Not applicable Availability of data and material