Twin Myths & Facts

From the NHS Website [1]

Myths about twins

There are many myths about twins. Here, we separate fact from fiction.

Myth: Twins run in families

There is no evidence that identical twins run in families. However, it is possible that a family could have a genetic predisposition to non-identical twins, probably due to the woman having a predisposition to releasing more than one egg each month when she ovulates.

Myth: Twins skip a generation

It is a common misconception that twins skip a generation in families. You may have heard, for example, that if your father is a twin but you're not, you're more likely to have twins yourself. There's no evidence to support this. However, some women may have a genetic predisposition to hyperovulation, where they produce more than one egg during a menstrual cycle. This makes it more likely that they will have twins. If this is the case, twins are just as likely to be born to each generation as they are to skip one.

Myth: Having lots of morning sickness means you’re pregnant with twins

Not necessarily. Although some mothers expecting multiple births report lots of morning sickness, other mothers who are pregnant with twins or more don’t experience any morning sickness. Some pregnant women have nausea and vomiting and some don’t, whether or not they’re carrying twins.

Myth: Twins speak their own secret language

Twins have an innate understanding of each other and, as a result, may speak in their own code. Also, because they spend so much time together, one may pick up words said wrongly by the other twin that they both understand, which can be perceived as a twin language by other people.

Myth: All pregnancies start out as twin pregnancies

It isn’t true that all pregnancies start out as twin pregnancies. However, thanks to early pregnancy scans, it has been discovered that more pregnancies than we thought do start out with two fertilised eggs.

It's possible that if you're scanned before 12 weeks, you'll see two foetal heartbeats and two foetal sacs, but one will have disappeared by the 12-week scan. This is because one of the embryos failed to thrive and it has been reabsorbed into the womb. This is referred to as vanishing twin syndrome and has no physical effect on the surviving baby.