U.S. twin birth rate 1980-2021
Since 1980 the U.S. birth rate for twins has risen significantly. As of 2021 the birth rate for twins in the U.S. was 31.2 per 1,000 live births. It is believed that an increase in the twin birth rate may be associated with an increased use of vitro fertilization and other assisted reproductive technologies in recent years.
U.S. twin births
Across the U.S. twin birth rates vary in a variety of ways. The U.S. states with the highest twin birth rates are Connecticut and Michigan. Ethnicity is another factor to be considered when investigating the twin birth rate. Since 1980 the U.S. twin birth rate has increased among all ethnicities; however, it has increased more among non-Hispanic black mothers and less among Hispanic mothers. And finally, age is another important factor in twin birth rates. As of 2019, mothers between the ages of 45-54 had the highest twin birth rates in the United States.
https://www.statista.com/statistics/276017/us-twin-birth-rate/