What is the Chance of Having Twins?

Whenever a celebrity announces a twin pregnancy, as Beyoncé did recently, many of us can’t help but speculate. Did she use fertility treatments to conceive? After all, it is commonly known that the chance of having twins is higher with in vitro fertilization (IVF). How likely are twins for moms who get pregnant naturally?

I don’t know if Beyoncé underwent IVF (and it’s really none of my business). But it did make me curious about the chance of conceiving twins (or more!) au natural. As you can imagine, it’s pretty slim.

According to the Centers for Disease Control and Prevention, there were nearly four millions babies born in 2014.  Of those, 135,336 twins arrived. So out of every 1,000 births, about 34 were twins, or 3.4%. Of course the possibility of triplets is much lower.  There were 4,233 triplets in 2014, making the chance of having three babies at once a one in 1,000 chance.

Smiling bearded caucasian man posing with his twin newborn babies with his wife in the background at the hospital room
Moms 35 and older have an increased chance of having twins.

A number of factors contribute to the likelihood of having multiples. Moms 35 and older have an increased chance of having twins. (Beyoncé is 35, in case you’re wondering). The chance of conceiving twins is also higher if you are of African descent, have already birthed a set of twins, or if anyone on your mother’s side had multiples, says WebMD. That’s just for fraternal, or non-identical, twins. Identical twins are the result of a single fertilized egg dividing. They’re believed to be purely random occurrences, with no genetic or other predictable history.

Moms who get pregnant through fertility treatments such as IVF have a higher chance of having multiples based on the number of embryos they choose to implant. The CDC’s report doesn’t call out which multiple-baby births might have been the result of fertility treatments. They do note that in 2012 an estimated 1.5% of all births that year were thanks to fertility treatments. Which would make the chance of twins just 2% for moms who conceive naturally!

The rate of twin births has increased dramatically over the years as both the average age of moms and the use of fertility treatments has increased. Since 1980 the rate of twin births is up 76%. That’s nearly double the number of twins born today than 40 years ago.

Do you have twins in your family? Would you like to have multiples if you could?