This study is a descriptive, cross-sectional, single-center study, conducted between April and September 2021 at the neonatology unit of the HA in Nouakchott, Mauritania. Nouakchott is the capital and the largest city of Mauritania, located on the Atlantic coast, with 1,491,958 inhabitants in 2023 (Figure 1). The HA is one of the main referral hospitals in the city, with a pediatric department comprising a neonatology unit equipped with eight incubators, four radiant warmers, and two bassinets.

We included all newborns aged 1 to 28 days who were hospitalized in the neonatology department with hemoglobin levels of 14.5 g/dL for preterm infants or 3.5 g/dL for full-term infants.

We excluded all newborns with congenital anomalies, those with inaccessible blood samples, and those born to mothers with chronic illnesses such as HIV/AIDS, diabetes, HTA, kidney/liver disease, malaria, and malignancies.

The minimum sample size was calculated on an estimate based on the number of newborns admitted to the neonatology department of HA in the same period (6 months) of the last year, 2020. For 600 newborns and a confidence level = 95% (Z=1.96, Z = 1.96, Z=1.96; margin of error = 5%), the recommended population of the study was 235 newborns.

Severe anemia was defined as a hemoglobin level below 7 g/dL in full-term newborns and below 10 g/dL in premature infants. Moderate anemia was defined as hemoglobin levels between 7 and 11 g/dL in full-term newborns and between 10 and 13 g/dL in premature infants. Sociodemographic and clinical data were collected using a pre-tested structured questionnaire translated into Arabic and other national languages during face-to-face interviews with mothers or guardians. The information collected included maternal age, education, occupation, place of residence, antenatal care follow-up, iron and folic acid supplementation, number of pregnancies, and history of bleaching or complications during pregnancy. Neonatal clinical data (fever, irritability, poor feeding), including neonatal birth weight, gestational age, Apgar score, and symptoms of infection, were extracted from hospital records using a standardized data extraction sheet.

Blood samples of 1.5 to 2 mL were collected via venous puncture under sterile conditions. Samples were placed in EDTA tubes. The hemoglobin concentration was immediately analyzed using a HemoCue^® Hb 301 System. The rest of the samples were kept at 4 °C and analyzed within 2 h using a Sysmex XP-300. Additional tests included CBC, C-reactive protein (CRP), bilirubin level, blood grouping, Rhesus factor, and blood culture, when available. CBC and CRP values > 6 mg/L and blood culture were used to diagnose neonatal infections.

All data collectors received training, and data collection tools were pre-tested. Laboratory samples were handled by qualified personnel, and standard operating procedures were followed to minimize errors. Data entry was double-checked for consistency.

Analysis data were entered into Microsoft Excel and exported to SPSS version 21 for analysis. Descriptive statistics were used to summarize variables (frequencies, percentages, means, medians, and interquartile ranges). Chi-squared tests were used to analyze associations between anemia and categorical variables such as infection, maternal anemia, and Rhesus incompatibility, with significance threshold of p < 0.05. Hemoglobin distributions were analyzed by age group and anemia severity (mild—11–13.4g/dL; moderate—7–10.9 g/dL; and severe—<7 g/dL).

The study was approved by the institutional committee of the faculty of Medicine, University of Nouakchott. Written informed consent was obtained from the parents or legal guardians of all newborns included in the study.

Among the 242 newborns hospitalized between April and September 2021 in the neonatology department of HA in Nouakchott, 57% were male and 43% female (sex ratio = 1.35). Most mothers (72%) lived in urban areas. The mean maternal age was 27.4 years (range: 16–44). About 45% had completed secondary education, and 35% received regular antenatal care. Iron and folic acid supplementation during pregnancy was reported by 58% of mothers.

The global prevalence of neonatal anemia was 16.5% (40 out of 242). Among anemic newborns, 55% were full-term and 45% preterm. Mild anemia accounted for 60.0%(24 out of 40), moderate for 30.0%(12 out of 40), and severe anemia for 10%(4 out of 40) of cases (Table 1). The median hemoglobin concentration was 11.2 g%dL (IQR: 9.8–12.4).

Neonatal infections were diagnosed in 40% of anemic newborns based on CRP levels and clinical signs. Rhesus incompatibility was noted in 22.5% of anemic cases. Low birth weight (<2500 g) was observed in 62.5% of anemic neonates. A significant association was found between anemia and infection (p = 0.03), as well as between anemia and lack of maternal iron supplementation (p = 0.02).

Treatment included antibiotics (40%), phototherapy (30%), and blood transfusion (15%), (Table 2). The mean hospital stay was 5 days (range :1–9). At discharge, 80% of newborns had fully recovered without sequelae, while 20% died during hospitalization.