The system of donor organs, this includes sperm and eggs, must abide by a good samaritan clause, or else the system does not work. If I donate blood, or sperm, it is the responsibility of the facility collecting it to deem it safe. I could possibly be held liable for endanging another if I knowingly falsified records about known diseases.
As for the obligation to be financially or emotionally responsible for the children produced, that distroys the system. If as you suggest they should be obligated to care for these children, then no one would donate.
If you wish to include financial responsibility, you would need to do so with an insurance policy, this would make the product even more expensive. Who would this hurt - the potential patients that wish to concieve.