Whether you’re hoping for twins or hoping to avoid getting a two-for-one pregnancy, there is no sure fire way to guarantee anything when it comes to conception. Yes, fertility treatments like IVF definitely increase your chances of becoming pregnant with twins, but what increases the odds of having “spontaneous” twins? Your chances of having twins depends on a range of factors. Here are a few that have some science behind them:
- Genetics
Heredity doubles your chances of conceiving twins, but only if the twins are on the mother’s side.
- Age
As you age, your chance of conceiving twins increases. Researchers have found that women over 35 produce more follicle stimulating hormone (FSH) than younger women, which may cause more than one egg to drop at ovulation.
- Height
Twins are more common in large and tall women than in small women. Experts believe it’s because taller women have higher levels of insulin-like growth factor (IGF), which boosts ovulation by upping the sensitivity of the ovaries to FSH
- Weight/BMI
Women with pre-pregnancy BMIs higher than 30 are significantly more likely to have fraternal twins than women with lower BMIs. Researchers believe it’s for the same reason that taller women have a higher chance of twins: higher levels of IGF.
- Previous pregnancies
With each pregnancy, the odds that you’ll have twins go up a little, possibly because with each pregnancy you’re a little bit older, which also increases your odds.
- You’ve had twins before
Yes, you can get pregnant with twins more than once! If you’ve already given birth to a set of twins, you’re significantly more likely to do so again.
- Diet
While scientists have not agreed on a clear set of dietary factors that could increase your chance of twins, there are some theories. One is that drinking a lot of cow’s milk can increase your odds of twins. This thought is based on the idea that insulin-like growth factor (IGF) is increased in women who drink a lot of milk, especially the milk of cows treated with growth hormones because their IGF is higher.
- African Heritage
Non-Hispanic black women have the highest chance of conceiving nonidentical multiples. Hispanics and Asians are on the other end of the spectrum with those of European/White ancestry falling somewhere in the middle.
The more factors you check off above the more you increase your odds of twins. But there is no magic twin pill, so all you can really do is cross your fingers and hope for the best, whether you are hoping for twins or not.