At some point during the trip, the pregnancy would most likely impede on the pregnant crew member's duties and abilities. It is still not fully known how the environment in a spacecraft would affect the development of a child aboard. It is known however that an unborn child in space would be more susceptible to solar radiation, which would likely have a negative effect on its cells and genetics.[99] During a long trip to Mars it is likely that members of craft may engage in sex due to their stressful and isolated environment.[100]