Can male children bank sperm to preserve their fertility?

For prepubertal boys it is not an option because they don’t produce mature sperm at that point and they don’t ejaculate yet so there's no way of getting sperm from them. But for pubertal boys, it is a good option of preserving their fertility. However, young teenagers may not be able to donate sperm just because they’re not used to doing that yet. And so what we found is that, usually around age 14, so higher than age 14 is when they can start donating sperm to be banked or frozen, but before 14 usually they’re unsuccessful. And so, we usually don’t even—we can present the option to the family but they are usually unsuccessful in freezing sperm.