Child Mortality: The Biggest Improvement Nobody Talks About

From roughly 1 in 4 children in 1950 to under 1 in 25 today

Roughly 1 in 4 children died before their fifth birthday in 1950. Today the figure is under 1 in 25. Measured by lives saved, it is the largest improvement in human welfare of the last century — and it explains most of what else has changed in global demography.

What the measures mean

Two related figures get used interchangeably and should not be:

• Infant mortality rate — deaths before age 1, per 1,000 live births.
• Under-five mortality rate — deaths before age 5, per 1,000 live births. This is the headline figure most international comparisons use, because the first five years carry most of childhood risk.

The global under-five rate has fallen from roughly 220 per 1,000 in 1950 to about 37 today. National figures range from under 3 in Iceland, Finland, Japan, and Singapore to above 100 in the worst-affected countries.

What children actually die of

The causes are concentrated, and most are preventable or treatable with interventions that are neither new nor expensive:

• Complications of preterm birth — the leading single cause worldwide.
• Pneumonia — still one of the largest killers, and largely treatable with antibiotics.
• Birth asphyxia and trauma — strongly tied to whether a skilled attendant is present at delivery.
• Diarrhoeal disease — deaths fell enormously with oral rehydration therapy, a solution of salt, sugar, and clean water.
• Malaria — concentrated in sub-Saharan Africa, where most childhood malaria deaths occur.

Roughly half of all under-five deaths now occur in the first 28 days of life. That share has risen — not because newborn deaths increased, but because deaths in later childhood fell faster. The remaining problem has shifted toward the hardest window to address.

Why it fell

No single breakthrough did it. The decline came from several cheap interventions applied at scale:

Vaccination against measles, tetanus, diphtheria, and pertussis. Oral rehydration therapy. Antibiotics for pneumonia. Insecticide-treated bednets for malaria. Skilled birth attendance. Clean water and sanitation. Improved maternal nutrition.

What these share is that none is technologically advanced. The barrier was never invention; it was distribution. That is why progress tracked closely with health-system reach and political stability rather than with medical research.

The demographic consequence

Falling child mortality is the hinge that everything else turns on, and its effect is counterintuitive: it ultimately lowers birth rates.

When most children died young, families had many children partly to ensure some survived to adulthood. As survival became reliable, that logic dissolved — usually within a generation. This is the mechanism behind the global fertility decline, and it is why the two curves always move together, with mortality falling first.

It also drove the population surge of the twentieth century. Deaths fell before births did, and that gap produced the fastest growth in human history. In that sense the same fact explains both why population exploded and why it is now levelling off.

Where progress has stalled

Improvement has not been uniform. Sub-Saharan Africa still accounts for the majority of under-five deaths, and several countries facing conflict or state collapse have seen progress halt or reverse. A child born in the worst-affected countries is still roughly 30 times more likely to die before five than one born in Western Europe.

For how child deaths sit within total global mortality, see our deaths by cause breakdown.