States with the Most and Least Twins

States with the Most and Least Twins

States with the Most and Least Twins
States with the Most and Least Twins. © Pamela Prindle Fierro 2016

Sometimes it seems like there are twins everywhere you look. But when you analyze the data of twin births in the United States, you can see that there are some definite concentrations in certain geographic locations.

States with the Highest Number of Twin Births

The states with the highest rate of twin births are New Jersey, Massachusetts and Connecticut. In 2014, the latest date range for which data is available, the national rate of twins was 33.9 per 1,000 live births. But these three states were well above that.

States with the Highest Rate of Twin Births

  • New Jersey 43.1/1,000 live births (13,364 twin births)
  • Massachusetts 42.8/1,000 live births (9,249 twin births)
  • Connecticut 40.5/1,000 live births (4,410  twin births)

Twin births are measured in relation to the total number of live births in the state. So why is there such a large concentration of twins in these northeastern states? Several theories are offered to determine why the rates are so high in these states. 

An article 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. 

States with the Most Twin Births

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 twin births. For example, 46,559 twins were born in Calfornia during 2014. But the rate of twin births was only 31 per 1,000 live births, below the national level. 

States with the Most Twin Births

  • California 46,559 (31/1,000 live births)
  • Texas 36,543 (31.2/1,000 live births)
  • New York 26,996 (37.7/1,000 live births)


States with the Least Twins

Perhaps you are also interested to know where the twins are not concentrated. 

States with the Lowest Twin Birth Rate

  • New Mexico 24/1,000 live births (1,911 twin births)
  • Arizona 28.5/1,000 live births (7,370 twin births)
  • Arkansas 28.8/1,000 live births (3,299 twin births)

States with the Least Number of Twins

  • Vermont 599 (33.1/1,000 live births)
  • Wyoming 722 (31.5/1,000 live births)
  • Delaware 983 (29.9/1,000 live births)


Table I–11. Twin, triplet, and higher-order multiple births, by state: United States and each state, 2012–2014. National Vital Statistics Reports, Vol. 64, No. 12, December 23, 2015