The single greatest threat to a child’s life varies based on the child’s age, location, access to healthcare, and other socioeconomic factors. However, globally, the leading causes of death for children under age 5 are preterm birth complications, pneumonia, birth asphyxia, diarrhea, malaria, neonatal sepsis and infections.
Newborn and Infant Mortality
For newborns and infants under 1 year old, the greatest threats are complications related to preterm birth, birth asphyxia, infections, and congenital abnormalities. Preterm birth complications are the leading cause of death for children under 5 worldwide, responsible for about 1 million deaths in 2015. Preterm babies are at higher risk of respiratory distress, infections, cerebral palsy, and long-term disability. Birth asphyxia, or lack of oxygen at birth, can damage the brain and other organs. Sepsis, pneumonia, diarrhea and malaria are also major threats that can quickly lead to death in newborns and infants due to their underdeveloped immune systems.
Preterm Birth Complications
Preterm birth, defined as birth before 37 weeks gestation, affected about 10% of pregnancies globally in 2014. Complications from preterm birth are the leading cause of death globally for children under 5, responsible for nearly 1 million deaths in 2015. The most common causes of preterm birth include multiple pregnancies, infections, and chronic conditions. Babies born prematurely are at higher risk for breathing problems, feeding difficulties, cerebral palsy, developmental delay, vision problems, and hearing impairment.
Birth Asphyxia
Birth asphyxia, or lack of oxygen at birth, affects around 4 million babies worldwide each year and leads to nearly 1 million newborn deaths annually. Asphyxia can occur when the umbilical cord becomes wrapped around the baby’s neck during delivery or when the placenta separates from the uterus too early. This lack of oxygen at birth can damage the brain and other organs. Preventative measures for birth asphyxia include skilled care during delivery, resuscitation equipment, and emergency transport to higher-level facilities when needed.
Sepsis and Infections
Sepsis, pneumonia, meningitis, diarrhea and other infectious diseases are major threats to newborns and infants. Neonatal sepsis affects 5.3 million children annually, causing over 600,000 newborn deaths per year, predominantly in developing countries. Sepsis is caused by bacterial, viral or fungal infections that spread through the bloodstream, damaging tissues and organs. Pneumonia, diarrhea and malaria also pose major risks among newborns and infants due to their underdeveloped immune systems. Access to clean delivery practices, vaccines, breastfeeding, handwashing and antibiotics are key to preventing many neonatal infections.
Congenital Abnormalities
Congenital abnormalities affect approximately 3% of newborns globally and are responsible for over half a million newborn deaths annually. Some common lethal congenital abnormalities include heart defects, neural tube defects, Down syndrome, and thalassemia major. Genetic factors, maternal health conditions like obesity or diabetes, infections during pregnancy, drug and alcohol abuse, pollution and poor maternal nutrition can increase risks for congenital disorders. Prenatal screening and diagnostic tests allow for early detection and management.
Early and Late Childhood Mortality
For children ages 1-5 years, infectious diseases remain the biggest threat, along with injuries, malnutrition and congenital disorders. Pneumonia, diarrhea, malaria, measles and injuries together accounted for over half of global deaths in this age group in 2015. Malnutrition was a contributing factor in about 45% of deaths among children under 5. Globally, under-5 mortality dropped by 59% from 93 deaths per 1,000 live births in 1990 to 39 deaths in 2017. However, 5.4 million children under age 5 still die each year, mostly from preventable causes.
Pneumonia
Pneumonia is the leading cause of death globally among children 1-5 years old, responsible for over 900,000 child deaths in 2015. Pneumonia is a lung infection caused mainly by bacteria, viruses or fungi. The disease spreads through respiratory droplets from coughing or sneezing. Young children are especially susceptible due to their developing immune systems and smaller airways. Pneumonia can be prevented through vaccination, handwashing, adequate nutrition and environmental health. Case management includes antibiotics, oxygen therapy and supportive care.
Diarrheal Diseases
Diarrhea was the second leading killer of young children globally in 2015, causing over 500,000 deaths in children under 5. Rotavirus is the most common cause of severe diarrhea in young children. Other viral, bacterial and parasitic infections can also cause diarrhea. Diarrhea leads to fluid loss, which can quickly turn fatal in small children. Oral rehydration solutions, zinc supplementation, vaccines for rotavirus and cholera, breastfeeding, hand washing with soap, clean water and sanitation all help prevent infectious diarrhea.
Malaria
Malaria caused over 300,000 deaths in children under 5 in 2015, mostly in sub-Saharan Africa. Malaria is a parasitic infection transmitted through mosquito bites, causing high fever, chills, flu-like illness and anemia. Young children and pregnant women are most severely affected. Malaria is preventable and treatable with insecticide-treated mosquito nets, indoor spraying, timely diagnostic testing and artemisinin-based combination therapies. However, progress against malaria has stalled in recent years due to barriers like funding gaps, drug and insecticide resistance, and weakened health systems.
Measles
Measles caused over 130,000 deaths in children under 5 in 2018, a spike from previous years due largely to outbreaks in Africa and Southeast Asia and gaps in vaccination coverage. Measles is one of the most contagious diseases, transmitted by respiratory droplets through coughing and sneezing. Initial symptoms include high fever, cough, runny nose and pink eye, followed by a characteristic rash. Measles can be prevented through two doses of a safe, effective and inexpensive vaccine. Immunization, vitamin A supplementation, and swift medical care are key to controlling measles.
Injuries
Injuries such as drowning, falls, burns and road accidents are a leading cause of death for children ages 1-5 years globally. Over 300,000 children under 5 die from injuries each year, mostly in developing countries. Toddlers are particularly vulnerable to falls, burns, poisonings and drownings as they become mobile and explore their environments. Safe guarding water sites, child-proofing homes, supervision, seated car restraints and focused injury prevention programs can help reduce preventable child injury deaths.
Regional Variations
While the major causes of newborn and child death are consistent globally, the distribution and specific risks vary across regions based on socioeconomic factors and health system capacity.
Sub-Saharan Africa
Sub-Saharan Africa shoulders the heaviest burden of newborn and child deaths, with 1 in 13 children dying before their fifth birthday in 2017. The region has the world’s highest child mortality rate along with the highest birth rate. Leading causes of death are preterm birth complications, pneumonia, intrapartum complications, sepsis, malaria and diarrhea. Risk factors include high rates of infectious disease, poverty, malnutrition, and inadequate access to clean water, sanitation, vaccines and skilled medical care, especially among the rural poor.
Southern Asia
Southern Asia has the second highest child mortality rate, with a under-5 mortality rate of 57 deaths per 1000 live births as of 2017. Leading causes include preterm complications, pneumonia, diarrhea, birth asphyxia, sepsis and congenital abnormalities. Poor sanitation infrastructure, malnutrition and low birthweight babies contribute significantly to the region’s high newborn mortality in particular. India alone accounted for nearly a quarter of global under-5 deaths in 2017.
United States
In higher income countries like the United States, the leading causes of newborn and child death shift to complications of preterm birth, congenital malformations, sudden infant death syndrome (SIDS) and injuries. The U.S. under-5 mortality rate was 6.5 deaths per 1000 live births in 2017. Racial, geographic, and economic disparities persist in the U.S., with black and indigenous children facing higher risks of infant mortality. Prevention efforts focus on improving access to prenatal care and counseling, reducing elective early deliveries, back sleeping to prevent SIDS, and safety interventions like pool fencing and car seats.
Global Progress and Challenges
The global under-5 mortality rate dropped by 59% from 93 deaths per 1000 live births in 1990 to 39 deaths in 2017. Vaccines, improved nutrition, oral rehydration therapy, antibiotics and malaria control measures drove much of this progress. However, the global decline has slowed in recent years. Barriers include stagnating health funding in developing nations, ongoing conflicts and emergencies, wider socioeconomic disparities, climate hazards and uneven access to quality care and life-saving interventions.
The Sustainable Development Goals call for ending preventable newborn and child deaths by 2030. Experts estimate that 15,000 under-5 deaths occur daily from preventable conditions like preterm birth, pneumonia diarrhea and malaria. Strategies to reach SDG child survival targets include expanding vaccine coverage, improving childbirth and newborn care practices, increasing access to essential medicines and boosting health budgets in poorer nations. Investments in clean water, sanitation, girls’ education and poverty reduction are also key for long-term impact.
Conclusion
The greatest threats to a child’s survival vary based on age, location and access to healthcare. However, preterm birth complications, pneumonia, diarrhea, malaria, neonatal infections, birth asphyxia and injuries lead globally across age groups. Under-5 mortality remains unacceptably high in certain regions like sub-Saharan Africa and Southern Asia. Sustained efforts to prevent, detect and treat these leading child killers through vaccines, essential medicines, improved nutrition, skilled care and public health measures are critical for saving lives. Major global progress is possible with targeted interventions and adequate investments in maternal, newborn and child health.