We retrospectively recorded files of newborns admitted and deceased during a 24 months’ period from January 1^st, 2017 to December 31^st, 2018 in the neonatal unit of Laquintinie Douala Hospital. It is a teaching hospital located in the Littoral region, in the economic capital of Cameroon. It is a tertiary care health facility. The neonatal unit is divided into 3 areas (red area or emergency room, orange area for referred newborns and green area for newborns coming from the hospital maternity ward). It has a capacity of 38 places including 28 beds, 7 incubators and 3 neonatal resuscitation tables. It has a reception ward, an intensive care unit and a kangaroo care unit for premature babies. The medical team is made up of 3 pediatricians and 4 general practitioners. The nursing team is made up of 25 nurses divided into 4 teams.

Some strategies like the perinatal network and emergency care voucher had improved management of neonatal emergencies. The perinatal network is a team of 112 maternal and child caregivers who are posted in public and private health facilities in Douala and neighboring towns. Communication is established through a social network. Each caregiver gives key data for adequate referral destinations and rapid admission of critically ill newborns. It helps to increase survival of neonates in vital distress. Moreover, they benefit from the emergency care voucher (called the green voucher) for drugs and emergency exams with deferred cost recovery.

We included records of all newborns who arrived alive and who died during hospitalization in the neonatology unit of the Laquintinie Douala Hospital. Records of newborns were included consecutively. Records of newborns who arrived deceased and those with incomplete records were excluded (Figure 1).

We collected data from neonatal unit registers and medical records. Data collection was performed with a pretested record and variables included:

· The socio-demographic characteristics of the mother (age, profession, level of education) and the newborn (age, gender, birth weight, place of origin, means of transport);

· Obstetrical data (parity, gestational age, number of antenatal consultations, tetanus/antianemic/antimalarial prophylaxis, serologies performed, risk factors for neonatal sepsis, place and route of delivery, apgar score);

· The clinical characteristics of newborns (reason for admission, clinical signs, positive diagnosis, duration of treatment, time of death).

Neonatal mortality was defined as death that occurred within the first 28 days of life. Neonatal sepsis was considered for any newborn with infectious risk factors (prolonged rupture of membranes, per partum fever, urogenital infection in the third trimester, chorioamnionitis), clinical signs of infection (fever, hypothermia, jaundice, respiratory distress, seizures, refusal to breastfeed, pallor) and biological criteria (CRP greater than 20 mg/l, with or without bacteriological or radiological evidence of infection). Respiratory distress was considered for a Silverman score greater than 2/10. Neonatal asphyxia was defined as inability to establish a cry or autonomic breathing at birth with an alteration of the Sarnat score without any other identifiable etiologies. It should be noted that there was no gas measurement to measure blood pH and base deficiency. A poor Apgar score was defined as an Apgar score less than 7 at the 5^th minute. Small for gestational age (SGA) was defined as a birth weight less than 2500 g. Prematurity was defined as a gestational age less than 37 weeks’ amenorrhea.

The data were recorded using EPI-INFO software version 7.2.0. We used SPSS software version 20.0 (IBM Corporation, Chicago, USA) for statistical analysis. Continuous variables were expressed as median with the interquartile range. Categorical variables were presented as proportions, percentages or frequencies. We used the Chi square test to compare proportions between groups. Quantitative variables were compared using student’s t test. We used a logistic regression to identify factors associated with neonatal mortality. A p-value < 0.05 was considered statistically significant.

This study received ethical approval from the institutional board review of the Faculty of Medicine and Pharmaceutical Sciences of Douala (N˚ 1760 CEI-Udo/04/2019/T). Administrative approval was obtained from the head office of the Laquintinie Hospital in Douala (N˚ 03795/AR/MINSANTE/DHL/CM). The principles of anonymity and confidentiality were respected in reporting the results.

During the study period, 2061 newborns were admitted to the neonatal unit of LDH. Among them, 275 newborns died, for an overall neonatal hospital mortality rate of 13.3%. We excluded 5 files due to missing data. We retained 270 files (Figure 1).

In total, 77% of deceased newborns were admitted on the first day of life. Out of the deceased newborns, 149 (55.2%) were male and the sex ratio was 1.2. According to the place of delivery, 173 (64.1%) newborns were delivered at Laquintinie Douala Hospital and 80 (29.6%) newborns were coming from another health facility in the town. More than half of deceased newborns were transported by families prior to admission (Table 1).

A total of 263 (97.4%) deceased newborns were born in a maternity. Vaginal delivery was effective in 205 (75.9%) cases. Cesarean section had been performed for 65 (24.1%) newborns. The main indications for cesarean section were acute fetal distress (27.7%) severe pre-eclampsia (23.2%) and cephalo-pelvic disproportions (12.3%). The median weight (IQR) of newborns at birth was 2052 (1347 - 3200) grams with a range of 700 g to 4800 g. More than half of the newborns who died were born prematurely. The median Apgar scores were 6 (5 - 8) at the 1st minute and 7 (6 - 9) at the 5^th minute, respectively. Resuscitation was performed in 104 newborns (38.51%).

The median age of mothers (IQR) was 28 (22.7 - 31) years with a range of 17 to 43 years. The 25 - 29 age group represented 34.1% of mothers, followed by the 20 - 24 age group (30.4%). Mothers working in the informal sector represented 60.4%, followed by pupils and students (26.3%). More than half of the mothers (n = 204) had made less than 4 antenatal consultations during their pregnancy (Table 2). They received two doses of tetanus toxoid vaccine. Antimalarial and anti-anemic prophylaxis had been observed in most mothers. All mothers were tested for HIV and 12 (4.4%) were positive. Of the 270 mothers, 21 (8.1%) had per partum fever and 150 (44.4%) had premature rupture of membranes within 6 hours.

The median age of mothers (IQR) was 28 (22.7 - 31) years with a range of 17 to 43 years. The 25 - 29 age group represented 34.1% of mothers, followed by the 20 - 24 age group (30.4%).

Mothers working in the informal sector represented 60.4%, followed by pupils and students (26.3%). More than half of the mothers (n = 204) had made less than 4 antenatal consultations during their pregnancy (Table 2). They had received two doses of tetanus toxoid vaccine. Antimalarial and anti-anemic prophylaxis had been observed in most mothers. All mothers were tested for HIV and 12 (4.4%) were positive. Of the 270 mothers, 21 (8.1%) had per partum fever and 150 (44.4%) had premature rupture of membranes within 6 hours.

Prematurity, poor Apgar score and acute fetal distress were the main reasons of admission in neonatal unit (Table 3). According to vital parameters, 148 (55.4%) deceased newborns had hypothermia on admission, 102 (38.2%) had normal temperature and 17 (6.4%) had fever. The median heart rate (IQR) was 138 (126 - 150) beats/minute. The median respiratory rate (IQR) was 45 (35 - 54) cycles/minute. More than half of the deceased newborns (72.6%) had an oxygen saturation greater than 95%.

Others*: Jaundice, convulsions, small-for-gestational-age, prolonged rupture of membranes, cough, vomiting.

The newborns showed several signs of severity at the same time. Cyanosis and desaturation were found in 175 (64.8%) and 179 (66.3%) newborns, respectively. Only 15 (5.6%) newborns had fever.

The main causes of neonatal death were prematurity (n = 102; 37.8%), neonatal sepsis (n = 92; 34.1%) and neonatal asphyxia (n = 66; 24.4%) (Figure 2).

More than half of the newborns (n = 168; 62.2%) died at night (between 5 p.m. and 7 a.m.). More than 2/5 newborn deaths occurred between 24 and 72 hours after their admission to the neonatal department respectively in 2017 (40.4%) and (41.4%) 2018.

Newborns whose mothers were in the informal sector [OR = 5.49; 95% CI 0.86 - 34.77; p = 0.07] and a primary level of education [OR = 2.42; 95% CI 1.98 - 2.85; p = 0.0001] had a significantly elevated risk of death.

As for obstetrical data, multiparity [OR = 2.61; 95% CI 0.51 - 13.19; p = 0.001], a number of antenatal consultations less than 4 [OR = 3.29; 95% CI 0.80 - 13.56;p = 0.09] and malaria during pregnancy [OR = 2.28; 95% CI 1.44 - 3.12; p = 0.0001] increased the risk of neonatal death.

Delivery by cesarean section [OR 0.59; 95% CI 0.43 - 0.82; p = 0.0001] was a protective factor. However, resuscitation [OR 1.63; 95% CI 1.25 - 2.13; p = 0.0001] and extreme prematurity [OR 6.45; 95% CI 4.68 - 8.89; p < 0.001] significantly increased the risk of death as reported in Table 4.

The neonatal mortality rate in our study was 13.3%. This result is lower than the mortality rate of 20.3% found by Kedy Koumet al. in the same hospital in 2015 [6]. Owusu et al. also reported a higher mortality rate than our study in Ghana in 2018 [8]. Our results are similar to those of Koki Ndombo et al. in Cameroon in 2017 who had a mortality rate of 15.7% [7]. This result could be explained by the new strategies adopted especially the perinatal network in Douala. This network facilitates the transfer of newborns from one health facility to another. In addition, the systematic use of an emergency care voucher for any newborn hospitalized and the improvement in the working conditions of caregivers could explain the decline in neonatal mortality at DLH.

The main causes of neonatal mortality were prematurity (37.8%), neonatal sepsis (34.1%) and neonatal asphyxia (24.4%). These results are similar to those found in most studies of neonatal mortality [6] - [11].

The high proportion of deaths linked to prematurity could be justified by predominance of very preterm babies in our sample. Indeed, newborns whose gestational age is less than 32 weeks are more likely to die due to the immaturity of most vital functions. Several studies have reported a high mortality rate in this group [11] [12] [13]. They are at risk of respiratory, infectious and hemodynamic complications. In a context of scarce resources, the Kangaroo method recommended by WHO could reduce the mortality rate of premature babies [14].

Neonatal sepsis was the second leading cause of death in our study. This result suggests the need to strengthen the screening and management of maternal infections in the 3rd trimester of pregnancy as well as hygiene protocols during labor. This result could also suggest the selection of germs resistant to the usual antibiotics. Hence the interest for each neonatal department to adapt antibiotic therapy to the local bacterial ecology, while reducing the pressure of germs’ selection through validated protocols.

Neonatal asphyxia was the third leading cause of death in our study. These deaths could be explained by the inadequate monitoring of pregnancy, the circumstances of childbirth, insufficient equipment and caregivers trained to handle neonatal resuscitation in our peripheral health structures. Nakibuuka et al. in Uganda reported a significant reduction in neonatal mortality after 3 training sessions in neonatal resuscitation and use of the partograph in Kampala [15]. It is therefore essential to ensure continuous training in neonatal resuscitation and the adequate equipment of birth rooms.

More than half of the deaths occurred during on-call hours (between 5 p.m. and 7 a.m.). Wang et al. in Shanghai made the same observation [16]. This situation could be explained by the absence of a sufficient number of qualified caregivers during the night, resulting in a decrease in the follow-up of newborns. The strengthening of on-call teams seems to be necessary.

Newborns whose mothers were in the informal sector and had a primary education had a significantly high risk of death. In an American study in California, university level was a protective factor [17]. This suggests that mothers with a low level of education have limited access to health care due to the financial means and are less aware of alarming signs.

Regarding obstetrical data, less than 4 antenatal visits and malaria during pregnancy increased the risk of neonatal death. This observation highlights the importance of high quality antenatal care for the well-being and survival of the newborn.

For newborns, cesarean section was a protective factor. This observation has also been made in California [17]. Our findings raise the question of timing and indications of cesarean section in our context assuming that this intervention should improve the prognosis of the mother and the child.

A gestational age less than 32 weeks increased the risk of death. Aguilera et al reported a high risk of death in preterm babies in Chile [18]. This is explained by the immaturity of these newborns and their high susceptibility to infections.

The burden of neonatal mortality in sub Saharan Africa is well known. Many interventions are made to improve survival of newborns in Cameroon. The retrospective view of this study did not allow us to observe care practices at real time and identify any delays at different levels of intervention. However, we were able to identify the causes and factors associated with neonatal mortality in the neonatal department of this tertiary care hospital.