This was a descriptive and analytical cross-sectional study conducted from January to June 2024 (6 months). It was carried out in the Neonatology Department of the Issaka Gazoby Maternity Hospital in Niamey, one of the level 3 referral centers in the country’s healthcare system.

The study involved premature newborns cared for in the department during the study period.

2.2.1. Inclusion Criteria

All premature newborns with usable medical records, i.e., with the fewest missing variables, were included.

2.2.2. Non-Inclusion Criteria

Newborns who had not completed their treatment in the department (discharged against medical advice, absconded) were not included.

2.2.3. Sampling

All newborns meeting the inclusion criteria during the study period were recruited.

The variables related to the sociodemographic characteristics of the mothers (age, origin, level of education), their medical history, and pregnancy follow-up (number of prenatal consultations, type of pregnancy, use or non-use of intermittent preventive treatment for malaria with sulfadoxine-pyrimethamine, iron and folic acid supplementation). The characteristics of the newborn were also studied (gestational age, route and mode of delivery, sex, measurements at birth, physical and paraclinical examination data, and associated comorbidities). Finally, therapeutic and evolutionary aspects (medical care, evolution, and causes of death) were explored.

Prematurity was defined as birth before 37 weeks of amenorrhea (WA). It was considered moderate for a gestational age between 32 WA and 36 WA + 6 days, very high between 28 WA and 31 WA + 6 days, and extreme between 22 WA and 27 WA + 6 days. Gestational age was determined based on the date of the last menstrual period and/or early ultrasound. It was then supplemented, if necessary, by the Farr score or the Ballard score. Hypotrophy was defined as a weight < 10th percentile relative to weight on gestational age curves, eutrophy between the 10th and 90th percentile, and macrosomia above the 90th percentile. Birth asphyxia was defined as an APGAR score < 7 at 5 minutes. The diagnosis of neonatal infection was made based on the 2002 ANAES diagnostic criteria [6]. Congenital malaria diagnosis is based on clinical signs (fever, respiratory distress, neurological disorders, etc.) with a positive thick smear in the newborn and the mother. Hypoglycemia was defined as a blood glucose level < 0.25 g/L (1.4 mmol/L) during the first three days of life and < 0.30 g/L (1.6 mmol/L) thereafter. Anemia was defined as a hemoglobin (Hb) level ≤ −2 SD (standard deviations) from the mean hemoglobin level for age. Hypothermia was defined as a temperature below 36.5˚C.

Data processing and analysis were performed using Epi-Info version 7.2.4.0 and Microsoft Excel 2016. For the descriptive part, numbers and percentages were calculated. Pearson’s Chi-square test or Fischer’s exact test were used to investigate the relationship between qualitative variables (occurrence of deaths), with a significance threshold of 5% (p < 0.05). The odds ratio (OR) and its confidence interval (CI) were calculated to measure the association. Variables with a p-value < 0.05 were then selected for multivariate regression. In multivariate analysis, multiple logistic regression was performed to test the link between the explanatory variables and the central variable (occurrence of deaths). For the adjustment strategy, a step-down approach was used. The results were expressed as adjusted OR (aOR) with their 95% CI. Variables for which the aOR were different from 1 and statistically significant were considered factors associated with occurrence of deaths in premature newborns.

The study was conducted after approval was obtained from the Issaka maternity hospital authorities and the head of the neonatal department. The data collected will remain anonymous, and confidentiality and medical secrecy have been respected.

During the study period, 3908 newborns were admitted to the department, including 400 premature newborns, representing a frequency of 10.2%. The average age of mothers was 27.36 ± 6.62 [15 - 53 years]. In 66% of cases, they had no income-generating activity, and 65.75% had no education. A history of premature birth was found in 10% of mothers. The average number of antenatal care visits was 3 ± 1 [0 - 7]. Sulfadoxine-pyrimethamine intermittent preventive treatment for malaria and iron and folic acid supplementation were administered to 91.5% and 90% of mothers, respectively. Four cases (1.00%) of maternal death due to immediate postpartum complications were reported.

Table 1 shows the distribution of newborns according to type of pregnancy, prematurity, and trophicity. Most newborns were from singleton pregnancies (74.8%). Prematurity was moderate in 71.8% of cases. The average birth weight was 1786 ± 647.2 g [520 - 3430 g], with hypotrophy in 14% of newborns. The average birth length was 42.2 ± 6.2 cm [35 - 50 cm]. The average head circumference at birth was 29.9 ± 3.6 cm [17 - 37 cm]. Newborns were less than 24 hours old at the time of admission in 98.5% of cases [0 - 7 days]. The sex ratio was 1.3. The APGAR score was below 7 at five minutes in 32.5% of cases, and resuscitation was reported in 24.3%. The main clinical signs on admission were respiratory distress (52.8%), hypothermia (19.3%), and poor neurological behavior (20.8%). Anemia and hypoglycemia were found in 29% and 5.3% of newborns, respectively. Thick drop was positive in 26.5% of cases. Associated pathologies were neonatal asphyxia (38%), neonatal infection (35.8%), and congenital malaria (16.5%).

Table 1. Type of pregnancy, prematurity, and trophicity.

Antibiotic therapy was administered to 97.8% of newborns, as well as artesunate-based antimalarial treatment in cases of congenital malaria (16.5%). Care in a kangaroo mother care unit was provided to 22.5% of newborns. The average length of hospital stay was 2 days [1-38 days]. Most newborns (75.5%) stayed in the ward for less than 5 days. One hundred and seventy-one (171) deaths were reported (42.75%). The main causes of death, often associated with the same newborn, were neonatal infection (74.27%), perinatal asphyxia (43.27%), and anemia (11.11%). Deaths occurred between 0 and 3 days after birth in 69.59% of cases.

The bivariate analysis of factors associated with death are shown in Table 2. Deaths were more common among newborns born before 33 WA (79.5%) and less than 24 hours old at admission (96.5%), with a statistically significant relationship (p < 0.01). Deaths were also more common among male newborns (53.7%) and newborns from singleton pregnancies (73.7%), but without a statistically significant link (p > 0.05). Newborns referred from other health centers were twice as likely to die as those admitted directly (OR = 2.21 [1.46 - 3.32]; p < 0.01). Newborns with asphyxia at birth and neonatal infection were 8 times and 7 times more likely to die, respectively (p < 0.01). In multivariate analysis (Table 3), the associated factors of death were gestational age under 33 WA, the reference, neonatal asphyxia and neonatal infection (aOR > 1; p < 0.01).

Table 2. Bivariate analysis of associated factors to death.

Table3.Multivariate analysis of associated factors of death.