Down syndrome is one of the most common chromosomal conditions, occurring in about 1 in 700–1,000 live births worldwide. In the United States, this works out to roughly 6,000 babies born with Down syndrome each year.
How common globally
- Globally, Down syndrome occurs in around 1 out of every 1,000 babies born.
- In many higher‑income countries with widespread prenatal screening, current estimates are closer to about 1 in 700 births.
How many people have it
- In 2019, there were an estimated 1.6 million people living with Down syndrome worldwide.
- In the United States, estimates suggest around 250,000–350,000 people are living with Down syndrome, depending on the method used.
Regional differences
- Some regions, such as parts of Western Europe and Southern Latin America, have reported higher age‑standardized prevalence rates, around 65 cases per 100,000 people.
- Differences between countries are influenced by factors like average maternal age, access to prenatal testing, and local laws or practices around pregnancy termination.
Quick comparison
Measure| Typical estimate
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Global births with Down syndrome| About 1 in 1,000 live births.7
US births with Down syndrome| About 1 in 700 live births (~6,000/year).13
Global living with Down syndrome| About 1.6 million people (2019).9
US living with Down syndrome| Roughly 250,000–350,000 people.146
