Narrator: Scientists have studied a lot of
pregnant animals in space,
including salamanders, fish, and rats,
but not humans.
Over 60 women have traveled to space,
yet none were pregnant during the trip,
let alone gave birth while floating in zero gravity.
But with talk of future space colonies and cities on Mars,
there's a good chance that one day
humans will give birth somewhere beyond Earth,
and that brings up some interesting questions.
What will it be like?
How will space babies look?
And ultimately, how will giving birth in space be different?
The most obvious difference is the low-gravity environment,
and without the aid of Earth's gravitational pull,
it might make it more difficult for the mother
when it comes time to push the baby out.
Plus, if one day women lived in space permanently,
some of the risks of pregnancy
would be much greater than on Earth.
For one, without the stress of Earth's gravity,
her bones lose density.
Studies show that astronauts, for instance,
lose 1% to 2% of their bone density
for every month spent in space,
and that would be especially concerning for giving birth
because the pelvis could fracture in the process.
In fact, doctors recommend that women with brittle bones
avoid a natural birth altogether,
which could mean births in space
would be left to other methods.
Scott Solomon: That could lead to
an increased reliance on C-sections
for childbirth for people living in space.
Narrator: That's Scott Solomon,
an evolutionary biologist and professor at Rice University.
He walked us through what space might do
to generations of humans born in low-gravity environments.
We already know that the way
we give birth influences our anatomy.
For example, the size of our heads
is restricted by the size of our mothers' birth canals.
Solomon: With more C-sections, that could lead to
larger heads in our descendants
because they wouldn't be constrained
by the size of the birth canal.
Narrator: And down the road, larger heads
wouldn't be the only major change.
We may also change color, says Solomon.
That's because in space we have less protection
against harmful space radiation like cosmic rays,
so to counteract that, we may evolve
Solomon: new types of skin pigments, like the melanin
that protects our skin from ultraviolet sunlight on Earth.
That could mean that future generations living beyond Earth
will evolve to have different skin colors.
Narrator: The more melanin you have,
the darker your skin.
So Solomon predicts that people living in space
may develop darker skin over time.
But he says these changes might take centuries or millennia
for enough time for many generations
of women to give birth in space.
Solomon: Eventually, people living in space
could evolve to be different enough from people on Earth
that we would consider them to be different species.
Narrator: But for now, we just need
one very brave woman to pave the path.