We live to learn... And today I learnt about something really interesting called superfetation that previously I would bet it's just impossible to occur in humans.
But first, what is superfetation?
In layman's terms it's when during a pregnancy there are two (or more I guess) embryos in a different developmental stage. For example, imagine a woman getting pregnant and then getting pregnant again like a month or two later. And both embryos growing at their own pace.
Now, that does occurs in some animals...But humans?
Well, it turns out that there have been a few reported cases of human superfetation in the past!
Like one case in 2017 when a surrogate mother in the U.S. bore two babies. At first it was thought it was just twins but in reality the second was from her and her partner and was conceived about a month later!
The same year there was also a case in Turkey when a woman became pregnant twice, a month apart and gave birth to both kids on October. This was the 12th such case reported in the medical records.
And there was also a case in 2020, when a woman in Wiltshire, England, gave birth to fraternal twins that were conceived three weeks apart!
There's also this 2008 paper reporting one such case:
We report the case of a dichorionic-diamniotic pregnancy in which a discordance in the size of the fetuses was observed as early as the first trimester. This discordance in size was maintained over time and the two fetuses continued their respective growths. We suggest the very rare phenomenon of superfetation as a diagnosis because less than 10 cases are described in the literature. Even though a formal proof of the diagnosis is difficult to obtain, the elements described in this article rally in favor of this hypothesis.
So, yeah I guess cream pies during pregnancy aren't as fool proof as you might think 😂
One thing is for sure. This could lead to some really awkward conversations when both embryos survive birth.
"Hey dad, how come Johnny is just a month older? Who's the adopted one?"
Fun stuff 😂
Here are some links if you'd like to read more on the subject: