From January 1, 2023 to June 30, 2023, 2884 neonates were hospitalized in the neonatology unit of CHU-MEL in Cotonou. We recorded 211 cases of death during this period, representing a hospital prevalence of 7.31%.

In the 211 neonates included, 114 (54.03%) were female with a sex ratio of 0.9. The average age was 4.6 days ± 5.3 with the extremes of one hour and 26 days.

Neonates transferred from the delivery room of CHU-MEL represented 60.2%.

The average age of the mothers was 27.3 years ± 5.9 with the extremes of 15 years and 41 years. The most represented age group was 25 to 30 years old. The mothers of neonates were mainly workers (31.75%) and resellers (30.80%). In 75.4% of cases, the mothers lived in an urban area. In 52.1% of cases, the mothers were not in school. University level was in 10.4% of cases.

The average age of the fathers was 32.6 years ± 5.6 with the extremes of 17 years and 63 years. The fathers of neonates were mainly workers (42.2%) and resellers (12.8%).

The study revealed that 64.54% of mothers had less than 4 antenatal consultations.

The majority of mothers had at least one pathology during pregnancy. The threat of premature delivery was found at 34.9% followed by preeclampsia (26.7%), hemorrhages (12.8%) and bacterial infections (10.5%).

The majority of mothers had given birth by vaginal delivery (72.5%).

Term of birth

The average term of birth in our study was 31.4 weeks ± 2.2 with the extremes of 22.4 WA and 42.4 WA.

APGAR score and concept of resuscitation

The average score at the first minute was 6.2 ± 1.8 in the neonates included in our study versus 6.8 ± 1.9 at the fifth minute. Among the 211 neonates who died, 91 were resuscitated, i.e. 43.1%.

The distribution of deceased newborns according to their weight showed that 54.5% of them weighed less than 1500 g followed by those whose weight was between 1500 and 2500 g. For size, the average was 40.7 cm with extremes of 22 cm and 54 cm.

The most frequent reasons for admission in our study were prematurity (60.66%), respiratory distress (23.22%) and jaundice (3.79%), respectively. Figure 1 shows the distribution of neonates according to the reason for admission.

Nearly half of neonates (47.4%) were admitted to the neonatology unit after the first hour of life ( Figure 2 ).

The average age at death of neonates was 4.9 days ± 5.3 with the extremes of one day and 27 days. We noted 173 deaths in neonates during the first seven days of life, representing an early neonatal mortality of 81.5%.

The average length of hospital stay was 5.6 days ± 4.3 with the extremes of 1 and 25 days. Neonates who died between the 2nd and 3rd day of hospitalization represented 35.1% of the total number, followed by deaths during the 1st day of hospitalization (33.2%).

Prematurity was the main cause of neonatal deaths (41.7%), followed by neonatal infections (29.4%). The main etiologies retained are presented in Table 1 below:

In view of the results, the neonatal mortality rate of 7.31% at the neonatology unit of CHU-MEL in Cotonou during the study period was relatively high with an early neonatal mortality of 81.5%. This was a hospital prevalence which did not constitute a good reflection of the prevalence of neonatal mortality in Benin. It was higher than that observed by Harir et al. at Sidi Bel Abbes gynecology-obstetrics hospital of wilaya in Algeria and by Randriamanga RL et al. at the hospital center of Soavinadrianain Madagascar where it had been reported 5.3% and 5.8%, respectively [10] [11] . Conversely, this rate was lower than the rates of Koum et al. in 2015 in Cameroon [12] , by Nagalo et al. [13] in Burkina-Faso in 2013 and Vierin-Nzame et al. [14] in Gabon in 2009 which reported 20.3%, 13.1% and 14.3%, respectively.

The prevalence of our study, although high, still remains lower than that reported by Houssou M.et al. [8] in Benin in 2015 which was 18.7% and that of Noudamadjo et al. [9] in 2021 (16.8%) in Benin but in different regions. The fact that our prevalence is lower than that of other authors could be explained by the numerous advances in the care of neonates, which have improved in our country, especially the improvement of the technical platform with the acquisition of equipment such as non-invasive ventilation devices, resuscitation tables, radiant heaters, oxygen concentrators.

Our mortality rate, however, remains high compared to European studies where socio-economic conditions and access to care are better [1] .

These variations between studies could be explained in part by the size of the sample, differences in terms of hospitalization criteria, the severity of cases admitted to each structure and the quality of antenatal care provided in these establishments.

Table 2 presents some neonatal mortality rates found in different studies.

Female gender was the most represented in our study (54.03%) with a sex ratio of 0.9. This result is similar to that observed by Chelo et al. [17] who reported a sex ratio of 0.91. A male predominance was found by Houssou [8] (sex ratio = 1.2) in 2015, Noudamadjo [9] (sex ratio = 1.23) in 2021, all in Benin and Nagalo (sex ratio of 1.2) in Burkina Faso [13] .

The average age at admission of neonates in our study was 4.6 ± 5.3 days, which is similar to those reported in Morocco by El Hakioui in 2020 (6.5 days) [18] and Chabli in 2021 (4.8 days) [19] . It was nevertheless higher than the age of 2 days reported in Burkina Faso by Nagalo et al. [13] and Barro et al. [20] . Neonates whose age was less than or equal to 7 days of life were the most represented in our study as well as in the data found in the literature [12] [18] [19] . This high concentration of neonates in the early neonatal period is explained by the fact that many admissions were neonatal emergencies.

On the other hand, in studies carried out in developed countries, the age of neonates at admission was higher. This may be due to the prolonged stay in maternity wards of neonates at risk of complications [21] .

Maternal medical history and follow-up of the pregnancy:

Neonatal deaths occurred in 62.6% of cases among multiparous women. That is consistent with the study conducted by Manzar et al. in Pakistan who found a frequency of 70.1% among multiparous women [15] . In Sudan, a study reported a significant association between multiparity and low attendance at antenatal care services. Thus, multiparous women tend to rely on their experience of previous pregnancies and do not feel the need for prenatal checks, believing that they already know what to expect during pregnancy or childbirth [22] .

The follow-up of pregnancies makes it possible to detect high-risk pregnancies and monitor their progress. The health of the child during the first months of life depends largely on the conditions of the pregnancy [23] . In our study, only 35.54% of mothers had followed up their pregnancy with at least 4 antenatal consultations. The distribution of deceased neonates according to the implementation of the different prophylaxes by the mothers revealed that anti-malaria prophylaxis was effective in 46.9% of mothers for the intermittent preventive treatment IPT and 67.3% for LLIN. Mothers who received a deworming medication during pregnancy represented 42.7% of mothers and 73.9% of them were vaccinated against tetanus during pregnancy. The low socio-economic level of parents and the absence of health coverage could explain these worrying results despite the numerous reforms in terms of pregnancy follow-up (new recommendations of WHO), and the legal provisions making antenatal consultations compulsory and systematic in the Republic of Benin.

In Africa, several studies have also demonstrated the importance of antenatal consultations: mothers who did not have any consultation had a higher probability of losing their child before the 8th day; this risk decreases when the woman comes for consultation [24] - [26] . For example, in Nigeria, the study carried out by Akinyemi et al. found that a good follow-up of the pregnancy reduced the risk of neonatal death by 30% [27] .

The threat of premature birth (34.9%), preeclamsia (26.7%) and hemorrhages (12.8%) were the most common pregnancy pathologies in our study. Koum et al. [12] reported in their study that malaria was the main disease in mothers, while Harir et al. [10] found genital infections (49.39%) and high blood pressure (26.82%). During our study, hemorrhage was found in 12.8% of mothers whose neonates were included, which is similar to the results of Sidibé et al. (9.2%) in 2006 in Mali [28] .

These results show the multitude of pathologies that can occur during pregnancy and consequently, the importance of antenatal consultations in the fight against neonatal mortality.

The course of childbirth plays an important role in the survival of the neonate. Several factors come into play and the presentation of the fetus comes first. A delivery that is too long or too laborious can have significant consequences on the condition of the neonate at birth.

The rate of cesarean deliveries was 26.5%. This rate is higher than the rate of 10 to 15% recommended by WHO [28] . It is close to that found by Koum et al. [12] which is 24.3% but remains significantly lower than the result of Nagalo et al. [13] in Burkina Faso (42.8%). Some studies prove that delivery by cesarean section is a protective factor against neonatal mortality [29] [30] . The vaginal route seems to expose people to a greater risk of dystocia, a source of intrauterine hypoxia and asphyxia at birth and therefore of death if adequate neonatal resuscitation care is not applied [13] . In contrast, Akinyemi [27] reported that neonates born by cesarean section have significantly twice the risk of death. This could be explained by the fact that the indications for cesarean sections were either maternal rescue or acute fetal distress which exposes one to the risk of iatrogenic prematurity, neonatal asphyxia and therefore increases the risk of neonatal death.

The average term of birth in our study was 31.4 weeks ± 2.2 with the extremes of 22.4 weeks of amenorrhea and 42.4 weeks of amenorrhea. It is lower than that of Nagalo et al. [13] who reported a gestational age of 37.4 ± 3.53 WA with the extremes of 25 weeks and 43 weeks. This discrepancy could be explained by the fact that in the neonatology unit of CHU-MEL, even non-viable neonates (<25 WA) are hospitalized while the smallest term in the study Nagalo was 25 WA.

Premature infants were the most represented in our study population with a rate of 77.77%. This result is close to that of Harir et al. [10] in Algeria (89%) but is significantly higher than those of El Hakioui [18] in Morocco, Yenan et al. [30] in Ivory Coast and Cissé et al. [31] in Senegal who reported 26%, 30% and 47.3%, respectively. This could be explained on the one hand by the fact that our study is carried out in a neonatology unit of a referral hospital which receives more premature neonates and on the other hand, by the fact that nowadays, the risk of premature birth increases due to current lifestyle and stress which arise from social and professional pressures. As for the average term at birth, recruitment of neonates less than 25 WA in our study could also explain this difference. The average birth weight in our study was 1609.08 ± 798.35 g with the extremes of 250 and 3710 g. The majority of neonates had a birth weight lower than 2500 g (80.6%) and this result is similar to that of Harir et al. [10] (84.27%). However, it is higher than that found by Yenan [30] in Ivory Coast (60.21%). This disparity could be explained by the predominance of premature neonates in our study while Yenan observed more full-term neonates in his study.

The predominance of neonatal mortality among low birth weight neonates is due to their vulnerability during the first hours and days of their life, especially if they are premature. However, low birth weight is not only due to prematurity, but also to in utero growth retardation or a combination of both factors [13] . This is why it is necessary to pay increased attention to the prevention of low birth weight, in order to provide them with additional nutrition, warmth and care, which could significantly reduce neonatal deaths [6] .

The causes of neonatal death are often difficult to analyze because several causes can be associated. The absence of a death certificate and systematic autopsy in many countries often makes it difficult to find the main cause of death [19] . The predominant causes in our study were: prematurity (41.7%), neonatal infections (29.4%) and perinatal asphyxia (10.9%).

Globally, the causes of neonatal deaths vary by region. The main causes of neonatal mortality in developing countries are infectious diseases in 36% of cases (including sepsis, pneumonia, tetanus and diarrhea), premature births with its related complications (27%) and neonatal asphyxia (23%). The remaining 7% of deaths were linked to a congenital anomaly [4] . The causes also vary depending on the time of occurrence of death during the neonatal period. Neonatal infections especially predominate towards the end of the neonatal period. That is to say beyond the first week. Deaths due to prematurity and perinatal asphyxia are highest during the early neonatal period [32] .

Prematurity is as much a risk factor for mortality as it is a direct cause of neonatal mortality. According to the International Classification of Diseases, the cause of death is attributed to prematurity when death is the result of complications specific to prematurity or when it occurs in a very preterm baby. For example, if a moderately preterm infant develops an infection and dies, the death should be attributed to the infection while prematurity acts as a risk factor [6] .

Compared to international data, our prematurity mortality rate (41.7%) was close to those of Barro et al. [20] in Burkina Faso and Kingwengwe et al. [33] in the Democratic Republic of Congo which found rates of 42.8% and 44%, respectively. This high rate of death could be explained by the fact that premature neonates are fragile with immaturity of vital functions causing multiple complications that are difficult to manage in our context. Neonatology units in countries with limited resources like ours do not have a technical platform adapted to the care of premature babies with the unavailability of exogenous surfactant and the absence of parenteral nutrition.

At the neonatology unit of CHU-MEL, the acquisition and use of devices for non-invasive ventilation such as nasal CPAP have contributed to improving the management of respiratory distress in premature babies.

In countries with high neonatal mortality rates, approximately half of all neonatal deaths are due to infections and most of these deaths are preventable or treatable [34] . In our work, neonatal infection was the second leading cause of death inneonates (29.4%), all locations included (respiratory, neuro-meningeal, systemic, etc.). This result is similar to that found by Lahmini et al. in Morocco [35] between 2012-2016 (32.2%) and Dare et al. in Ghana [36] between 2004-2012 (29%). Other authors have noted higher rates. Vierin Nzame et al. in their study in Gabon [14] , indicated that 38.46% of deaths inneonates were associated with neonatal infections. Koum reported that they were responsible for 54.9% of deaths [12] . On the other hand, countries with low neonatal mortality rates generally have lower proportions of mortality from neonatal infection [34] . The risk of a child dying from a neonatal infection is eleven times greater in countries with very high mortality than in those with very low mortality [2] .

These high frequencies in our context could be explained by poor follow-up of pregnancies which prevents screening and management of risk factors for maternal-fetal infection and the lack of asepsis in the management of neonates.

Perinatal asphyxia is the third leading cause of neonatal mortality in developing countries [4] . We recorded 10.9% of neonatal deaths due to this pathology. This is consistent with the results of Kalondji et al. [37] in the DRC (10.3%) and Chabli [19] in Morocco (12.3%). Other authors have found higher rates: Ongoiba [38] in Morocco in 2010 (22.6%), Barro et al. [20] in 2016 (20.81%) and Nagalo et al. [13] in 2013 (20.9%) in Burkina Faso. The high rate of deaths from perinatal asphyxia could be explained by poor monitoring of labor. Indeed, good monitoring of labor by the partograph makes it possible to detect anomalies in order to initiate the necessary actions in time. The inadequacy of resuscitation in the delivery room and the absence of an adequate technical platform for the management of cases of asphyxia in neonatology could also be at the origin of the high rates.

The incidence of perinatal asphyxia must be reduced to lower the resulting morbidity and mortality. This requires the implementation of preventive measures such as the adequate monitoring of parturients during labor, the evacuation and transfer of parturients at risk from peripheral hospitals, the provision of means of resuscitation of neonates in a state of asphyxia emergency in peripheral hospitals, raising awareness of health professionals on the importance of multidisciplinary collaboration in general, especially obstetric and pediatric management.