Which U.S. State has the highest rate of twin births?
According to recent data, that would be Massachusetts, with 44.3 twin births per 1,000 births. This is followed by Connecticut (41.7) and New Jersey (41.1), which in previous years have taken the spot of the U.S. State with the highest number of twin births. Rhode Island comes in fourth, with 40.3.
An article last year in The Boston Globe suggests that Massachusetts offers a combination of “an unusually large number of pregnancies in older women” and “a heavy reliance on readily available infertility treatments.” Like New Jersey and Connecticut, Massachusetts has a large number of affluent clusters, where wealthier, highly educated career women pursue careers when they are younger and delay childbearing until they are older. Not only are older mothers more likely to conceive twins, but inversely, they are also more likely to have trouble conceiving, and thus pursue reproductive assistance. Reproductive treatments can be costly, but in Massachusetts, the costs are covered by insurance.
Although these states have the highest rates of twin births, they are not the states where the most number of twins are born in a given year. That’s because states with much higher populations, such as Texas, California, and New York, also see more total births.