The twin birth rate in the United States was 33.9 per 1,000 in 2014, according to the latest report from Center for Disease Control and Prevention. Though it is only slightly higher than 33.7 per 1,000 in 2013, it is an all-time record, said CDC. The most twins were born in three most populated states of California, Texas, and New York. And the title for the lowest twin birth rate went to New Mexico with just 24 per 1,000.

Twin Birth Rate In US Hits Record High, Rate For Triplets Drops

Twin birth rate rises 4% for African-American women

The report points out that the “twinning rate” has almost doubled from just 18.9 twins per 1,000 births in 1980. Last year, a total of 3,988,076 births were registered in the United States. The twinning rate did not change for white or Hispanic women from 2013 to 2014. But it continued to rise another 4% for African-American women. The report added that the general fertility rate ticked up 1% from 2013 to 62.9 per 1,000 women aged 15-44 in 2014. It was the first increase since 2007.

The CDC said in its report that the twin birth rate could be rising due to two factors: more women are having children at an older age, and more women are using fertility treatments like in vitro fertilization. Past studies have shown that conceiving babies at an older age increases the likelihood of having twins. The twinning rate has gone up in most years since 1980.

Birth rates for triplets and higher multiples fall 5%

The birth rates for triplets and higher-order declined 5% from 119.5 per 100,000 in 2013 to 113.5 per 100,000 in 2014, the CDC said. The rate for triplets and higher multiples rose between 1980 and 1998, but has declined more than 40% since 1998. Researchers said changes in fertility treatments are likely to have contributed to the decline in birth rates of triplets and higher multiples.

The CDC noted that there was a 9% decline in the birth rate among teen mothers in the age group 15-19 since 2013. The birth rate among teen mothers plummeted to 24.2 births per 1,000. CDC said it was a “phenomenal” change as it was an all-time low figure. The birth rate among women in early 20s fell by 2% to 79 per 1,000.