Background
Birth asphyxia is defined by the WHO as a failure to initiate and sustain breathing at birth.1 It happens when the blood flow to or from the fetus is cut-off or when gas exchange is compromised before, during or after childbirth. Birth asphyxia can cause multisystem organ failure, severe metabolic acidosis, hypercarbia, progressive hypoxaemia, newborn encephalopathy and possibly death.2 Based on the appearance, pulse, grimace, activity and respiration (APGAR) score in the 1st, 5th and 10th min of life, birth asphyxia can be categorised as mild, moderate or severe.2
In the first month of life, 2.4 million children worldwide died in 2020. Approximately 6700 newborns die per day, which accounts for 47% of all children under the age of 5 who pass away, up from 40% in 1990. With 27 deaths per 1000 live births, sub-Saharan Africa had the highest newborn mortality rate in 2020.1
Birth asphyxia, along with severe infections and preterm birth, is one of the primary causes of neonatal fatalities worldwide, accounting for an estimated 900 000 deaths each year.3 4 It is also estimated to account for approximately 23% of all newborn deaths globally.4 With mortality rates of 26.7% for newborns and 11.3% for children under the age of 5, respectively, birth asphyxia is the second-leading cause of newborn mortality in Ethiopia.5
The Sustainable Development Goals were adopted by the United Nations in 2015, with the goal of lowering newborn mortality to less than 12 per 1000 live births by 2030.6 The Ethiopian government has also undertaken multiple strategies to achieve this target, including promoting the development of emergency obstetric and newborn care services with the goal of improving neonatal and maternal health.7 However, newborn deaths continue to be a major public health concern.
Birth asphyxia has a wide spectrum of complications that can damage the newborn’s motor, sensory, cognitive and psychosocial development.8 9 Even though the vast majority of newborns suffering from birth asphyxia recover quickly, a small number may develop hypoxic-ischaemic encephalopathy (HIE).10 Around 20%–30% of HIE infants die in the neonatal period, and 33%–50% of survivors have permanent neurodevelopmental problems such as cerebral palsy and mental retardation.11 12
There are various factors that increase the chance of death in newborns who have asphyxia. Risk factors for HIE include prematurity, maternal fever, multiple pregnancies, maternal anaemia, neonates who require resuscitation, neonates who have convulsions, prolonged capillary refill time, stage of HIE, low APGAR score (0–3), coma, prolonged seizures that are resistant to treatment, end-organ dysfunction and congenital brain malformation.13–16
Identifying predictors of mortality in asphyxiated newborns is critical for developing effective therapies and implementing critical measures on time. However, factors influencing death in asphyxiated newborns in Ethiopia have not been thoroughly studied. Moreover, the majority of previous research used logistic regression analysis, but in the current study, Cox proportional hazard regression analysis was used. This choice was made because the Cox model offers advantages over logistic regression in time-to-event data and survival analysis. It handles time-to-event variables, provides more statistical power and offers interpretability through easily understandable HRs, making the results more accessible to clinicians and non-statisticians. Therefore, this study was aimed at determining the incidence and predictors of mortality among newborns suffering from birth asphyxia in selected hospitals in West Shewa Zone, central Ethiopia.