It would be unethical to restrict a group that has the potential for genetic disorders to be banned from having children. This would be another form of racism. Some races are prone to more disorders than others. Just because there is a possibility that something will happen, it does not necessarily mean that it will actually happen. At a certain age women that have children may have genetic issues, but there is no rule that they are no longer allowed to have children.
Everyone should be able to make the decision of whether or not to have children whether they have genetic disorders or not. Are we saying that one life is more valuable than another? My husband nor I are in any high risk groups yet we still had a child with special needs. There are no guarantees no matter what we do.