So, You Want To Have Twins? Chances for Multiple Births

So, you want to have twins?

Interested in knowing what your chances are for multiple births. Currently in the U.S., there are 31 pairs of twins for every 1,000 babies born. That's up 65 percent in the past 20 years!

Why such a huge increase? Much of it's due to advances in assisted reproduction, of course, but there are also other factors at play, at least when it comes to fraternal twins (identical twins occur at random, so they're even more of an exciting surprise!). Your chances of seeing double (or more) go up if:

You have twins in your family. Heredity plays a role — but only on the mom's side. Even if your partner's family tree is loaded with dynamic duos, that won't increase your own odds of conceiving twins.

You're African-American. Black women are a bit more likely than Caucasians to have twins;

if you're Asian or Hispanic, then you're a bit less likely to get two-for-one.

You're an older mom-to-be. As you age, your chances of conceiving twins multiply.

You've been pregnant before. With each pregnancy, the odds that you'll have twins go up.

You've had twins before. Lightning can and does strike twice! If you've already borne a set of twins, look out — you're twice as likely to do so again.

You're undergoing fertility treatment. About 20 to 25 percent of women taking ovary-stimulating drugs or undergoing in vitro fertilization (IVF) will conceive twins or higher-order multiples.

You're overweight. Recent studies have shown that obese women are twice as likely to give birth to fraternal twins as those who aren't obese.

You're tall. The same studies found that taller women tend to face higher odds of having fraternal twins.