No matter where they live, many people eventually end up having kids, even in some of the most out-of-the-way spots on the planet. But, will they be able to live and work in space and have children? Or on the Moon? Or on Mars? Humans being humans, they will very likely try. Whether they succeed or not depends on a lot of factors.

One vision of Mars habitats that will provide shelter for astronauts as they learn to explore the planet. Eventually, they could be raising families on the Red Planet, in more extensive habitats that may well be underground. What will those children be like?. NASA

As humans prepare for a future off Earth, mission planners are finding answers to a number of questions about long-term space residency. One of the most perplexing is "Can women get pregnant in space?" It's a fair one to ask since the future of humans in space depends on our ability to reproduce out there.

Is Pregnancy Possible in Space?

The technical answer to that question is: yes, it's possible to become pregnant in space. There's nothing known about being in space that would prevent egg and sperm from uniting to make a baby. Of course, a woman and her partner need to be able to actually have sex in space in order to for those cells to get together in the first place. Additionally, both she and her partner must be fertile. Cycles infertility can be checked, and the mom and dad could then choose the right time to make that space baby. However, there's more required than "doing the deed." It turns out there are significant other hurdles that stand in the way of having what it takes to make a baby and then remaining pregnant once fertilization takes place.

Barriers to Child-bearing in Space

The primary problems with becoming and remaining pregnant in space are radiation and low-gravity environments. It's important to understand both.

The Moon has practically no atmosphere and no way to filter out harmful radiation. Humans living there would face some radiation danger from solar particles and cosmic rays. This could have a profound effect on a couple's ability to start a family. NASA

Radiation can affect a man's sperm count, rendering him infertile, possibly permanently. It can also harm a developing fetus. Radiation hazards exist here on Earth, too, as anyone who has taken a medical x-ray or who works in a high-radiation environment knows. It's why both men and women are usually supplied with protective aprons when they get x-rays or other diagnostic work. The idea is to keep stray radiation from interfering with egg and sperm production. Once an embryo is created, it's subject to the same radiation dangers as the mother.

Conditions that Could Interfere with Pregnancy

Let's say that conception happens after a couple gets together on the space station or during a trip to Mars or even after they land on the Red Planet. The radiation environment in space (or on Mars) is severe enough that it would prevent cells in the fetus from replicating. Thus, no baby would be brought to term.

Mars has a thicker atmosphere than the Moon, but it still is not enough to shield humans from radiation. This is another place where humans could face difficulties conceiving and birthing children. Credit:NASA/JPL-Caltech/MSSS

In addition to the high radiation, astronauts live and work in very low-gravity environments. The exact effects are still being studied in detail on lab animals (such as rats). However, it's very clear that a gravity environment is needed for proper bone development and growth. When astronaut Scott Kelly (and others) spent long periods on the International Space Station, they showed significant changes in their health. Similar issues could affect a developing fetus.

Such atrophy is why astronauts have to exercise in space regularly in order to prevent muscle atrophy and loss of bone mass. A growing embryo or fetus could be permanently altered, right down to the DNA.

Solutions to the Radiation Problem

Clearly, if people are to venture out into space on a more permanent basis (like extended trips to Mars) radiation hazards need to be minimized, not just for the adults but for any possible children born on the trips. But how to do that?

Astronauts taking extended trips into space will be on ships that are likely not to provide the heaviest radiation shielding. Once they get to Mars, for example, they'll be subjected to a lot of radiation on the surface that is not stopped by the thin atmosphere. Also, the lower gravity on Mars (and on the Moon, for those who migrate there), will be an issue.

The Orion crew capsule (shown here in water recovery testing) is a typical crew-carrying spacecraft that is shielded to protect astronauts from most radiation. Special precautions and materials must be used to protect crew members. Future spacecraft will need similar protective environments. NASA

So if permanent residencies are ever going to exist on Mars or the Moon, like those proposed by Dr. Mae Jemison for the Hundred-year Starship, then better shielding technology would have to be developed. Since NASA is already thinking of solutions to these problems, it's likely that radiation will cease to become as big a threat as it is now.

Overcoming the Gravity Problem

The problem of a lower gravity environment may be more difficult to overcome if humans are to successfully reproduce in space. Life in low gravity affects a number of body systems, including muscular development and eyesight. So, it may be necessary to supply an artificial gravity environment in space to mimic what humans evolved to expect here on Earth.

The good news is there are some spacecraft designs in the pipeline, like the Nautilus-X, that employ "artificial gravity" designs. These use centrifuges that would allow for at least a partial gravity environment on part of the ship. Anyone who has ridden a ride such as the "Mission Space" experience at Disney World's EPCOT center has felt the gravitational effects that a centrifuge can supply.

The problem with such designs is that they can't yet replicate a full gravity environment, and even then occupants would be constrained to one part of the ship located in the centrifuge. This would be difficult to manage. Further exacerbating the problem is fact that the spacecraft needs to land. So what do people do once on the ground in a low-gravity environment on a place like Mars?

The Future in Space: No Kids in Space Yet

Ultimately, the long-term solution to the problem is the development of anti-gravity technology. Such devices are still a long way off. However, if spaceship technology could somehow manipulate gravity then it would create an environment where a woman could carry a fetus to term. Until that is a possibility, humans going to space currently are very likely using birth control to prevent stillbirths and miscarriages. If they are having sex, it's a well-kept secret. But there have been no known pregnancies in space.

Nonetheless, humans will have to face a future that includes space-born and Mars- or Moon-born children. These people will be perfectly adapted to their homes, and oddly enough—the Earth environment will be "alien" to them. It will certainly be a very brave and interesting new period in human history!

Edited and updated by Carolyn Collins Petersen.