American Women Having More Twins Than Ever

Mothers in the U.S. are getting more efficient when it comes to giving birth.

The country's twin birthrate hit 33.9 twins per 1,000 births in 2014, up from 33.7 twins per 1,000 births in 2013. That’s nearly double the rate from 1980, when it was 18.9 twins per 1,000 births.

That data was releasd in a report from the Centers for Disease Control and Prevention. The report also noted, however, that the upward trend didn't apply to other multiple births. Birthrates of triplets and higher-order births declined in 2014, from 119.5 per 100,000 in 2013 to 113.5 per 100,000 in 2014. That’s the lowest rate in 20 years and down more than 40 percent from the peak in 1998, when the birth rate of triplets and higher-order births reached a record 193.5 per 100,000.

Why more twins these days?

Researchers attributed the rise to two possible factors: More women are using fertility treatments, such as in vitro fertilization. (Changes in fertility treatments— such as implanting three or fewer embryos — have likely attributed to the decline in triplet and higher-order birthrates.)

Also, more women are having children at an older age. Studies have shown that having children later in life may increase the likelihood of having twins.

The average age of the mother at her first baby's birth rose slightly, from 26.0 years old in 2013 to 26.3 years old in 2014, according to the report.

Don't miss this week's Slice of History: The 1st Octuplets

Sourced from: Live Science, U.S.Twin Birthrate Hits All-Time High