The infant mortality rate measures how many babies die before their first birthday for every 1,000 born alive. Globally, roughly 4.9 million children die before age five each year, with the majority of those deaths occurring in the first month of life. The rate varies enormously by country, from as low as 1 or 2 per 1,000 births in parts of Europe and East Asia to over 70 per 1,000 in sub-Saharan Africa.
How the Rate Is Measured
Infant mortality is expressed as the number of deaths among children under one year old per 1,000 live births during a given period. Within that first year, researchers often break the data into two windows: the neonatal period (the first 28 days of life) and the postneonatal period (day 29 through the end of the first year). The neonatal period is by far the more dangerous. Premature birth, complications during delivery, infections, and congenital anomalies account for nearly 4 in every 10 deaths among all children under five, and most of those deaths happen within hours or days of birth.
The Global Picture
The world has made dramatic progress. Since 1990, the under-five mortality rate has dropped by about 60 percent, and neonatal mortality has fallen by 45 percent. Still, millions of preventable deaths persist, and at the current pace of decline, an estimated 27.3 million children under five are projected to die between 2025 and 2030. Nearly 13 million of those will be newborns in their first 28 days.
The United Nations’ Sustainable Development Goal target (SDG 3.2) calls for every country to bring its under-five mortality rate to 25 or fewer per 1,000 births and its neonatal mortality rate to 12 or fewer per 1,000 births by 2030. Many high-income countries cleared those thresholds decades ago, but dozens of nations, mostly in West and Central Africa, remain far above them.
Countries With the Highest and Lowest Rates
According to 2024 World Bank data, the five countries with the highest infant mortality rates per 1,000 live births are South Sudan (72), Nigeria (70), Niger (66), Somalia (65), and Liberia (63). In these settings, limited access to skilled birth attendants, clean water, vaccines, and postnatal care drives the numbers up.
At the other end, San Marino reported a rate of just 1 per 1,000 births. Andorra, Belarus, Czechia, and Estonia each reported a rate of 2. A long list of countries also sit at that 2 per 1,000 level, including Finland, Iceland, Japan, South Korea, Norway, Singapore, Slovenia, and Sweden. What these low-rate countries share is universal access to prenatal care, well-resourced hospitals, and strong public health infrastructure.
The United States Rate
The U.S. infant mortality rate sits at 5.41 per 1,000 live births as of the 12-month period ending in the third quarter of 2025, a slight decrease from 5.56 over the same period a year earlier. That places the U.S. well above most other high-income nations, a gap that has persisted for decades and is driven largely by disparities within the country.
Racial and Ethnic Disparities in the U.S.
The national average masks striking inequalities. In 2021, infants born to Black non-Hispanic women had a mortality rate of 10.55 per 1,000 births, more than double the rate for White non-Hispanic infants (4.36). Infants of Native Hawaiian or Pacific Islander women (7.76) and American Indian or Alaska Native women (7.46) also faced significantly elevated risk. Hispanic infants had a rate of 4.79, and Asian infants had the lowest rate at 3.69.
These gaps reflect differences in access to quality prenatal care, rates of chronic conditions like hypertension and diabetes before pregnancy, neighborhood-level stressors, and systemic inequities in how maternal care is delivered. The disparity for Black infants in the U.S. means their survival odds are comparable to infants in some middle-income countries, even though they live in one of the wealthiest nations on earth.
Leading Causes of Infant Death
The top causes globally and in the U.S. overlap significantly. Premature birth is the single largest contributor. Babies born too early have underdeveloped lungs, digestive systems, and immune defenses, making them vulnerable to infections and breathing failure. Birth complications, including oxygen deprivation during labor, are the second major category. Neonatal infections picked up during or shortly after delivery rank third, and congenital anomalies (structural problems present at birth, such as heart defects or neural tube defects) round out the top causes.
In the U.S. specifically, sudden infant death syndrome (SIDS) and other sleep-related causes remain a notable contributor beyond the neonatal period. These deaths tend to occur between one and four months of age and are closely tied to sleep environment.
What Reduces the Risk
At the population level, the interventions that have driven the global decline are straightforward: skilled birth attendants, clean delivery environments, access to emergency obstetric care, vaccinations, breastfeeding support, and clean water. Countries that invest in these basics see their rates fall reliably.
For individual pregnancies, prenatal care is the single most protective factor. Early and regular checkups allow providers to catch warning signs of preterm labor, preeclampsia, and fetal growth problems before they become emergencies. Folic acid supplementation before and during pregnancy significantly reduces the risk of neural tube defects, one of the most common congenital anomalies.
After birth, newborn screening programs can detect conditions that look normal at delivery but cause serious harm if untreated. For preterm infants, treatments like ventilators and steroids help stabilize breathing while the lungs finish developing. And for SIDS prevention, the most effective step is placing babies on their backs to sleep in a clear crib, free of soft bedding, bumpers, and toys. That single practice, promoted widely since the 1990s, cut SIDS rates in the U.S. by more than half.
Why the Rate Still Matters
Infant mortality is one of the most widely used indicators of a society’s overall health. It reflects not just the quality of medical care but the conditions surrounding pregnancy: nutrition, housing, environmental exposures, stress, and economic stability. A high rate signals systemic problems that affect adults too, just less visibly. The gap between a rate of 2 in Scandinavia and 72 in South Sudan represents not just different hospitals but fundamentally different circumstances for mothers and families from conception onward.