You’re not seeing double at the mall (OK, maybe you are … lay off the free samples at the wine shop). The number of twins born in the U.S. reached a record high in 2014 and has nearly doubled since 1980. What’s causing this odd increase in identical babies? There are some scientific reasons and possibly some strange ones.
According to a new report released this week by the Centers for Disease Control and Prevention, there were 33.9 twin births per 1,000 births in the U.S. in 2014. That’s higher that 2013, when the rate was 33.7 twins per 1,000 births, and nearly double the rate in 1980, when it was 18.9 twins per 1,000 births.
There are a couple of scientific explanations for this increase. Many U.S. women are waiting until they reach age 30 to have their first babies and the chances of having twins are higher in older women. Coupled with that is the increase in the use of fertility drugs and in vitro fertilization, both of which ups the odds of having a twin birth. However, the rate of triplet, quadruplet and even more-plet births – which should have also increased – has gone down. Could there be some other reason for the abundance of twins?
Here’s a creepy one. In the 1960s, the evil Nazi doctor Josef Mengele – who conducted experiments on twins before escaping from Germany to Argentina after World War II – reportedly showed up in the village of Candido Godoi in Brazil claiming to be a veterinarian named Rudolph Weiss. Besides birthing calves, Weiss also treated pregnant women in the village – women who later gave birth to blue-eyed blond haired twins. Megele/Weiss moved on before he could be positively linked to the twins. Later research found a gene that causes predisposition to having twins that may have been passed down among Candido Godoi mothers since the 1930s.
Then there’s the Nigerian village of Igbo-Ora which has the highest rate of twin births in the world, an average of 45 to 50 sets of twins per 1000 live births. Some experts studying this say the high birth rate is due to a natural fertility drug found in the skin of the cassava, a yam-like plant with an edible tuber root that is a common food in the village, while others go with genetics like Candido Godoi.
Mengele’s long dead and cassavas aren’t on the menu at any U.S. fast food restaurants, so the reason for the increase in twins in the U.S. is most like the age of the moms and fertility drugs.