Babies would not develop properly in outer space, a new research has revealed.
Embryonic stem cells behave very differently outside the pull of Earth's gravity, researchers suggest-a finding leading scientists to fret that procreation in space may be fraught with peril.
The microgravity that astronauts experience orbiting Earth on the space shuttle or International Space Station can ravage their bodies on lengthy missions, atrophying muscles, weakening bones and causing irregular heartbeats.
To advance longer and farther into space, researchers want to curtail these risks.
By analysing the effects of weightlessness on the cellular level, scientists in Australia now believe they have pinpointed the roots of its harmful consequences.
Microgravity apparently tampers with stem cells, which all other cells originate from. Stem cells normally act as a repair system for the body by replenishing its tissues.
By uncovering the origins of these problems, the investigators now hope to design remedies that can truly help fix them.
"Our research is headed toward creating countermeasures that can be utilized by biomedical intervention for astronauts," Live Science quoted Helder Marcal of the University of New South Wales, as saying.
In their experiments, researchers employed human embryonic stem cells, which possess the extraordinary ability to become any other cell.
To simulate microgravity on Earth, the scientists used a NASA-designed machine, which kept the cells nourished with oxygen and nutrients while constantly spinning to keep the cells in a state of freefall for 28 days.
After this experiment, the cells showed vast differences on the molecular level, with 64 percent of their proteins differing from those grown under normal gravity.
Specifically, these microgravity-exposed cells generated more proteins that degrade bone and fewer proteins with antioxidant effects. Antioxidants protect against reactive oxidants that can damage DNA.
Microgravity also influenced levels of a broad range of other proteins. These include those involved in cell division, the immune system, the muscle and skeletal systems, calcium levels within cells, and cell motility.
These findings in embryonic stem cells may not bode well for attempts at procreation in microgravity.
"The simulated microgravity experiments we are investigating don't seem to suggest a very positive outcome," said Marcal.
Some of the detrimental risks that microgravity may have on an embryo include inhibited bone maturation, heart and blood vessel alterations, delayed neural growth, and altered muscle tissue maturation, speculated Marcal.
"The effect that microgravity may have on a growing embryo or fetus would be similar to an adult body-however, much more detrimental.
"The adult body can adapt to some microgravity space environments however, what remains totally unknown is if an embryo can adapt to such an environment too," said Marcal.
The findings were presented at the Astrobiology Science Conference 2010 in Texas in April.