Double up: Factors that increase your chances of having twins

What is better than one bundle of joy? Two, of course! Twins have always held a certain fascination – even now, when multiple births are on the rise. But why are we seeing so many more twin births, and could you be doubling up?

Hormone treatments

Research indicates that around 30% of pregnancies conceived with the aid of gonadotropins (stimulating hormones) result in multiples. However, the incidence is varied and there’s still a chance of twins if you’re on Clomid (an oral medication that can be used to stimulate ovulation), but it’s slimmer than if you have IVF, for instance.

In the genes

Most people know if there are twins somewhere in the family tree, there’s a chance they’ll pop up again. What you might not know is that the likelihood is greater if those twins are fraternal. This may be because of the father’s “superior semen quality”, which makes it possible to fertilise more than one egg at a time, or because there is a genetic history of hyperovulation (in other words, releasing more than one egg in a cycle).

Age isn’t just a number If you’re older than 35, your body has started releasing larger amounts of Follicle Stimulating Hormone (FSH), because the older you get, the more stimulation your eggs require in order to develop. However, this also means your follicles might respond by releasing two eggs.

Height and weight

Although obesity can be a cause of infertility, it may also lead to multiple births since women with a BMI of over 30 produce more oestrogen which, again, overstimulates eggs, possibly leading to the release of two eggs in a cycle. When it comes to height, women who are taller than 5’5’’ produce larger amounts of a hormone called insulin-like growth factor (IGF), which increases ovulation.

Your contraception method Do you know those stories of women who fell pregnant as soon as they went off the pill? It happens because your body’s hormone levels are a little all over the place, which creates the ideal conditions for a twin birth.

Pre-existing pregnancies It seems the more children you have, the more you may (potentially) have. The reasons why aren’t quite understood, according to curejoy.com – nor is it clear yet why you may also have a higher chance of twins if you’ve recently had a miscarriage. Again, it may be because of crazy hormone levels.

Breastfeeding Far from being an effective contraceptive (as you might have heard), breastfeeding actually increases your chance of having twins. Also, if you’ve nursed for longer than six months, your body produces more IGF – and you know what that means!