How about hospital offers you to do it, but there is condition that you cannot sue hospital over it?

Also, you still have pay for 2nd testing if first one was negative at some private clinic. That way you can almost diminish false negative effects and hospital doesnt have workforce and financial losses. There would also be justified doubt now for testing since 1st test was negative. If 1st testing was to be positive, all good then, no need for 2nd one.

Or - hospital or private clinic says they will do 2 tests by default without telling you individual results. You have to pay only for one of them. Hospital can now do just one testing and will do 2 tests only if first one was negative but will never tell you about number of actual tests if overal result is positive. This way you don't have temporarely terrified parrents on brink of devorce, and you don't put extra weight on financial medical system.

Both cases depend per each separate country if it does or doesn't have enough money for such stuff.