And there’s still a lot of confusion about how twin pregnancies occur and whether you can actually increase your chances of having twins.
The short answer is – yes and no.
First of all, there’s two types of twins – identical or monozygotic twins and non-identical or dizygotic twins (commonly known as fraternal twins).
Every woman has the same chance of having identical twins. Identical twins occur when an egg is fertilised by one sperm and then the egg splits into two separate embryos.
It's a different case for fraternal twins - they form when two separate eggs are fertilised by two separate sperm - and some women are genetically predisposed to have a greater chance of having twins.
However, the following factors can increase your chances of having twins:
According to Huggies, you're more likely to have twins when you're older rather than younger. When you enter peri-menopause, your body will start releasing more than one egg each month. With more eggs, it's more likely that more than one egg will be fertilised.
An increase in oestrogen after the age of 35 also leads to a "fertility spike".
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Genetics do play a role in non-identical or fraternal twins. If you come from a family where fraternal twins are common, your chances of having non-identical twins are greatly increased.
This is simple maths - the more babies you have, the greater chance you have a falling pregnant with twins.
Women who have been pregnant before also have a greater chance of having twins. And women who have already had twins, will also have an increased likelihood of having twins again.
Any kind of fertility assistance like IVF or fertility drugs will also increase your chances of having twins, says Baby Center. IVF stimulates the ovaries and leads to more eggs being released each month, therefore increasing the odds of more than one egg being fertilised.
If you get pregnant while you're on the pill or just after you come off the pill, the likelihood of twins is increased. As Huggies explains, once you go off the pill your body will go through a "hormonal readjustment phase", which makes it easier for more than one egg to be fertilised.
According to Dr David Williams, women who eat a lot of sweet potatoes tend to have a higher rate of twins. The compounds found in sweet potatoes trigger the release of a follicle-stimulating hormone which stimulates the ovary to release more than one egg each month.
That old wives' tale about oysters also has some truth to it. Oysters are high in zinc and zinc helps with sperm production. So if your partner eats oysters it can increase the chances of his sperm fertilising two eggs at once.
Fertility specialists also recommend that women start taking a folic acid supplement at least one month before conception, and men should up their intake of green leafy vegetables, seeds and cereals to increase their little swimmers chances.
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Women with a BMI of 30 or over are more likely to conceive twins. However, given that the healthy BMI range is 20-25, doctors don't recommend maintaining this body weight for the purpose of having twins.
Also, oddly enough, taller women are more likely to have fraternal twins.
As Babble reports, women who are breastfeeding and producing prolactin are nine times more likely to fall pregnant with twins than women who aren't breastfeeding at the time of conception.
Have you had twins? Tell us about it in the comments below.