But you freeze the sperm at the peak of freshness. Then you wait and see how the donor does. If they live to a ripe old age without old age diseases, then go select their sperm. Otherwise, destroy it.
You can probably do this with eggs too. When a child is desired, select an egg and a sperm off the shelf, and there you go. Easy peasy. Your device ensures only munitions experts can procreate outside the system, and I think we'll need a lot of munitions experts in the ensuing generations.