What if an astronaut is pregnant in space?

What happens if an astronaut is pregnant in space? Chris Smith put this question to space doctor Christina Makaill...

Christina - As far as I'm aware, no one has been pregnant in space. But if we're sending people to Mars in the future it’s definitely something we need to consider. So I think there's two main things that would affect pregnancy in space and the first one's radiation and the second one is a lower gravity environment.

Radiation can affect fertility in males and females on Earth in things like CT scans, x-rays and things and obviously they will be exposed to a lot of radiation in space which could harm a developing foetus.

Chris - Is that because the radiation damages the DNA?

Christina - Yeah. So it can damage the DNA and the development so if you were to send a pregnant woman to space, the radiation she was exposed to, the foetus we would be exposed to the same amount.

Chris - How much radiation would she see? Because I thought that the whole idea of flying say the International Space Station at the altitude it does, about 400 km, is that it still protected within the envelope of the Earth’s magnetic field so it doesn't see that much radiation, or am I wrong?

Christina - It's a lower amount but it's higher than here. But especially on the way to Mars, for example, would be in deep space and you get much more radiation. And I think I worked out once, because I'm very sad, that it would be something like the equivalent of 2500 CT scans or something which is a lot. Before we send people to Mars in general, and especially pregnant, we would need some sort of barrier to that.

Chris - Because when Curiosity, the rover, flew to Mars, they actually use the radiation sensor for that to look at the dose it got during that journey, and I think the calculation was, were that a human being would have encountered an entire safe working load of radiation for an astronaut for their lifetime on that trip, and back?

Christina - Yeah. Well interestingly, before I talk about the gravity they did a study recently with mice sperm on the International Space Station and they sent up frozen sperm. Then they impregnated mice eggs here on earth and the control was just normal sperm from Earth and they didn't see a massive difference in the structure and the development of the foetus compared with DNA on Earth. So I think they found that space radiation didn't affect the production of viable offspring.

Chris - Could that not... sorry to interrupt you Christina because it occurs to me though that….. if you do that experiment the only embryos that are going to form are going to be ones from sperm that haven't been compromised, because you select for the healthy sperm that can still make a healthy mouse baby compared with if you've got really messed up sperm from radiation then they’re not probably going to be successful, so you might be counting the positives artificially?

Christina - So they think that from the study that the DNA damage was decreased or repaired after fertilisation if that makes sense. So basically it was encouraging that they found that actually once the sperm was fertilised it had a sort of positive effect.

But the other thing is gravity. That's a big thing. We can protect from radiation, we can find a way but we know that lower gravity affects the bones and the muscles and vision things like that. So because astronauts lose muscle mass and they lose bone density how's a foetus going to develop in that environment? Because it's such an important time obviously to develop their bones and muscles and things.

Chris - But the foetus is floating around in amniotic fluid, the bag of watery fluid inside the mother, so does that not create a situation of almost artificial gravity anyway or does the baby still end up sinking in there because it’s sort of neutrally buoyant within the water isn't it, it floats around already?

Christina - I know what you mean, but I still think that the lower gravity might have an effect. I mean we've never tested it in humans so I can't say for sure but I think that would be an issue. So if we could prevent the radiation and sort of make gravity environment similar to earth we could definitely do it. But here will be babies born Mars Mars and, interestingly, Earth will be an alien environment to them and they will develop to Mars gravity so it's interesting, it's an interesting time.