American mothers are seeing double more than ever before.
The CDC says the twin birth rate among U.S. women hit a record high in 2013.
33.7 out of every 1000 deliveries that year were twins, according to a report from the agency.
That's an increase of 2-percent from 2012.
Health officials say the uptick might be linked to women having children later in life and more use of fertility treatments.
While the number of twin births is up, the total number of U.S. deliveries is down.
There were 3.9 million U.S. births in 2013.