The dream of colonising Mars or living on the Moon is no longer just the plot of a Christopher Nolan film. However, as private companies like SpaceX and Blue Origin prepare to send tourists into the stars, a massive biological hurdle remains unaddressed.
Human reproduction is a finely tuned process on Earth, but in the harsh environment of space, our basic biology begins to falter.
While Nasa has focused on bone density and muscle atrophy, the impact of cosmic radiation and microgravity on sexual health has been largely ignored.
If we are to become a multi-planetary species, we need to understand how the void affects our ability to create the next generation.
CAN HUMANS ACTUALLY GIVE BIRTH IN SPACE?
On Earth, gravity plays a silent but vital role in our reproductive systems. Research published in the journal PLOS One indicates that microgravity can significantly alter sperm motility.
Without the pull of Earth, sperm cells often lose their direction, making natural conception much more difficult.
Furthermore, the fluid shift that occurs in weightlessness, where blood moves from the lower body to the head, can interfere with the physiological arousal required for intimacy.
DOES COSMIC RADIATION DAMAGE OUR GENETIC CODE?
Beyond the lack of gravity, the biggest threat is space radiation. According to a study in the Proceedings of the National Academy of Sciences, high-energy particles from the Sun and distant stars can cause irreversible damage to DNA.
On Earth, our atmosphere protects us, but in deep space, these rays can hit sperm and egg cells like tiny bullets. This leads to oxidative stress, which may cause birth defects or long-term infertility.
For women, the risk is even higher, as radiation can accelerate the depletion of ovarian follicles.
IS IVF THE ONLY SOLUTION FOR SPACE COLONIES?
Since natural reproduction faces so many hurdles, scientists are looking at assisted technology.
A breakthrough study in Stem Cell Reports showed that mouse sperm kept on the International Space Station (ISS) for several months could still produce healthy pups upon return to Earth.
This suggests that cryopreservation might be the safest way to transport genetic material.
We may reach a point where babies in space are not born naturally, but are instead the result of carefully shielded laboratory procedures to ensure their genetic health remains intact.
