The little scar in the middle of your abdomen marks the place where, for about nine glorious

months, all the nutrients you needed to grow and develop and survive flowed straight into

your bloodstream while you just floated around in a sac of amniotic fluid. But have you ever

wondered what was going on with your other bodily functions while you were in that enclosed

space? To put it a little more bluntly, did you, you know, pee and poop in there?

The answer to question #1 is yes, definitely: embryos start peeing after just two months

of development, around the time they first begin swallowing--and, therefore, drinking--amniotic

This does essentially mean that fetuses spend seven months drinking their own pee, but that's

actually not as gross as it sounds. For one thing, urine--unlike feces--is sterile, so

it doesn't contain bacteria that could make the fetus sick. Also, the waste products we

normally get rid of by urinating, like excess nitrogen, are instead filtered from the fetus

and delivered, through the umbilical cord, back to the mother for disposal.

And what about the waste we normally get rid of by pooping? Well, mom takes care of that,

too - indirectly. She digests food before it gets to the baby, absorbing nutrients like

sugar and protein into her bloodstream and then passing those nutrients to her fetus

through the umbilical cord. So most of the potential poop products stay with the mother.

The fetus's digestive system isn't totally empty, though: some waste does go there and

get broken down by acidic bile in the small intestines, producing a slimy, sticky greenish

mass called meconium. But, unlike the large intestine of everyone outside a womb, a fetus's

large intestine is mostly sterile and devoid of the billions of bacteria that break down

our waste and make up as much as 50% of the brown pulp known as feces.

So the green, sticky mass that forms in a fetus's small intestines eventually becomes

a green, sticky, and mostly bacteria-free mass inside the baby's first dirty diaper.

And in a way, it's the first--and last--clean poop in anyone's life.

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