Rate of Triplet Births Plummets in the U.S.
The rate of triplet and higher-order births dropped more than 40 percent between 1998 and 2014, according to a new report from the National Center for Health Statistics. (More than 90 percent of higher-order births are triplets.) This lowered rate represents a reversal of a trend seen in the 1980s and 1990s, when the rate of triplet and higher-order births rose steadily. Additionally, the rate decline recorded in the N.C.H.S. report was seen nationwide, with Oklahoma and Louisiana the only states showing a slight increase -- 8 percent and 4 percent, respectively.
The study's lead author, Joyce A. Martin, points out that while older mothers are more likely than younger mothers to have a multiple birth, and even though the age of mothers has continued to increase, the rate of triplets has not kept pace. "So," she says, quoted in the New York Times, "the decline cannot be attributed to any changes in maternal age. We think the decline is likely largely related to changes in fertility therapies, particularly assisted reproductive technology."