It Turns Out You Can Get Pregnant While Being Pregnant: Everything To Know About Superfetation Twins

A woman has made headlines for becoming pregnant with one embryo while already being pregnant with another—but how common is this phenomenon.
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When it comes to medical queries, questions about pregnancy are some of those most frequently asked. 

This is not only because a whole bunch of strange things can happen to our body when we become pregnant, but also because (thanks to a history of medical studies only looking at men) we’re still learning a lot about the female body

If you have ever found yourself asking Dr Google whether a woman can become pregnant with one child while already being pregnant with another, then you might have a good reason to. 

A Perth mother, Sandra Searle, has made headlines for becoming pregnant twice in less than three weeks in a very rare phenomenon known as a superfetation pregnancy. 

Seale and her partner David were unaware that they had already conceived naturally when they successfully implanted an embryo through IVF, 18 days later. The result, ‘twins’ Poppy and Michael, were born nine months later. 

If you’re finding the story hard to believe then you might be wondering what a superfetation actually is, and how common this phenomenon really is.

Superfetation pregnancy
A superfetation pregnancy is highly rare but not impossible. (Credit: Getty)

What Is A Superfetation Pregnancy?

A superfetation pregnancy involves getting pregnant when you’re already pregnant. Usually, your body undergoes a myriad of changes to make it pretty much impossible to become pregnant when you’re already growing an embryo—however, in rare cases, a new pregnancy makes it past those barriers. 

It’s also important to note that superfetation babies are not twins—this is because the embryos didn’t form during the same menstrual cycle, and are technically, different gestational ages. This means that the first embryo will be more developed than the second embryo when born. 

However, superfetation pregnancies aren’t completely dissimilar to twin pregnancies—the fetuses do share the same womb, develop together and in most cases, are delivered together. 

For this reason, it’s not uncommon for superfetation babies to be raised as twins when born. 

Superfetation twins
Superfetation born children aren’t actually twins. (Credit: Getty)

How Common Is A Superfetation Pregnancy? 

For anyone worried about the likelihood of experiencing a superfetation pregnancy, then you will be pleased to know that the odds are not in your favour. In fact, superfetation pregnancies are so rare that there are only around ten known cases in the world. 

However, experts believe it’s likely a number of cases are unknown and unreported. 

So, why are these pregnancies so rare? Basically, your body is very good at preventing a pregnancy from occuring when you’re already pregnant—so good in fact, that most superfetation pregnancies have involved the use of assistive reproductive technology (ART) or IVF.

Is A Superfetation Pregnancy Dangerous? 

Most superfetation pregnancies aren’t dangerous to the mother or babies, however as most babies are delivered together, there’s a concern that one of the babies will be born premature. 

Usually, superfetation cases involve babies that are only a few gestational weeks apart. In these cases, medical providers will advise parents on the best time to deliver to ensure two healthy babies. 

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