Getting pregnant in space would be an interesting (albeit unethical) experiment, because we have no idea if it's even possible.
According to Millis, weightlessness could cause a miscarriage or ectopic pregnancy. And the high levels of radiation in space could cause cell deformation and mutation in the fetus.
It's likely that the bone structure of the fetus would not form correctly in microgravity, says Millis.
"If sex were successful, it is virtually certain that any resulting fetus would not survive the pregnancy," he said.