Multiples Print States With the Most and Least Number of Twin Births By Pamela Prindle Fierro Updated June 21, 2019 More in Ages and Stages Multiples Through the Years Babies Preschoolers Toddlers School-Age Kids Tweens Teens Young Adults View All 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. The rate of twin births rose 76 percent from 1980 to 2011 from 18.9 per 1000 to the high of 33.9 per 1000 in 2014, but it has stabilized or trended slightly down from year to year. Triplet and higher-order multiple births have dropped since their high in 1998 and continue to decline each year. States With the Highest Rate of Twin Births © Pamela Prindle Fierro 2016 The states with the highest rate of twin births are New Jersey, Massachusetts, and Connecticut. In 2016, the national rate of twins was 33.4 per 1,000 live births. But these three states were well above that, and they have held their top position for a few years. States With the Highest Rate of Twin Births Connecticut 41.3/1,000 live births (4,463 twin births)District of Columbia 40.4/1,000 live births (1,170 twin births)New Jersey 40.1/1,000 live births (12,381 twin births)Massachusetts 38.3/1,000 live births (8,228 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 Stephen Simpson/The Image Bank/Getty Images 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 46,150 (31.1/1,000 live births)Texas 37,664 (31.3/1,000 live births)New York 25,879 (36.4/1,000 live births) States With the Least Twins Kittichet Tungsubphokin / EyeEm / Getty Images Perhaps you are also interested to know where the twins are not concentrated. States With the Lowest Twin Birth Rate New Mexico 23.9/1,000 live births (1,832 twin births)Arizona 29.6/1,000 live births (7,606 twin births)Arkansas 29.6/1,000 live births (3,426 twin births) States With the Least Number of Twins Vermont 635 (35.7/1,000 live births)Wyoming 731 (32.01,000 live births)Delaware 993 (30.0/1,000 live births) Was this page helpful? Thanks for your feedback! Get diet and wellness tips to help your kids stay healthy and happy. Email Address Sign Up There was an error. Please try again. Thank you, , for signing up. What are your concerns? Other Inaccurate Hard to Understand Submit Article Sources Martin JA, Hamilton BE, Osterman MJK, Driscoll AK, Drake P. Births: Final Data for 2016. National Vital Statistics Reports, January 31, 2018, Vol. 67, No. 1.