Between 1980 and 1998, the triplet and higher-order multiple birth rate in the US soared from 37 to about 194 births per 100 000—a rise associated with older maternal age and a spike in the use of fertility treatments. But from 1998 to 2023, this rate dropped to 74 births per 100 000, a decline of 62%, according to a National Center for Health Statistics data brief.
