pregnancy test
photo: iStock

What with the Chicago Cubs winning the world series, Donald Trump winning the presidency, and "La La Land" turning their Best Picture Oscar over to "Moonlight," the last few months have proved the impossible, possible.

Now, courtesy of The New York Times' Science Q&A, there's one more item you can add to the list of things that are, in fact, possible: You can get pregnant while pregnant.

That's right: Through a process called "superfetation," it is possible to be impregnated with another child while already pregnant.

Just last year, an Australian woman gave birth to two babies, conceived 10 days apart. In 2009, an Arkansas woman gave birth to a healthy boy and girl, conceived three weeks apart. Doctors were able to distinguish the babies from regular twins because they had separate amniotic sacs.

While possible, the occurrence of a double pregnancy is extremely rare. There are only 10 recorded cases of superfetation in medical history, according to an article published in the French "Journal of Obstetrics and Gynecology of Reproduction."

pregnant woman
photo: iStock

Women's bodies are engineered to prevent double impregnation. Getting pregnant while pregnant requires some impressive flouting of evolutionary wiring.

First of all, you'd have to be ovulating while pregnant, which the vast majority of women are not. (As most women know, one of the perks of being preggo is that you don't have to deal with your period for nine months).

Second, your body actually puts a mucus plug in your cervix when you get pregnant, to prevent semen from getting into the womb. Some impressive little swimmer would have to find its way around this plug to even get to the uterus.

There's also the whole issue of another baby being in your uterus already. The fertilized egg has to find space to implant itself and grow, which is much easier when it doesn't have a uterine roommate.

pregnant woman
photo: iStock

The natural barriers to double pregnancies are so high that most doctors don't understand how superfetation occurs.

Dr. Jason James, medical director at Miami's FemCare Ob-Gyn, told SELF that "when [superfetation] does happen, no one is really sure how or why."

Sherry Ross, an OBGYN at California's Providence Saint John's Health Center, confirmed, telling SELF that the condition is "poorly understood and somewhat mystical for the medical community."

"Some medical phenomena we can't explain by any reason or logic," she concluded.