you are supposed to get the inserts befoe you sign the consent form - and time to read them, digest, and ask any questions you may have.
it is only after all this that you are able to give 'informed consent', after all.
I was refused the insert when I askd for it with dd1 - the nurse got extremely shirty, would not let me read it, threw the form at me to sign, and snapped 'if you read it you'll onlyhave questions afterwards'
(err, isn't that the point of being able to read the insert?)
she also went on to mutter lots about parents questioning 'since all that rubbish about autism' - very diplomatic since dd1 was in the system being assessed at that point 
anyway, luckily for me I had done my reading before going - it is possible to find copies of the inserts and information - so I told her in no uncertain terms that I would be complaining about her attitude, that I had questions I wanted answered regardless, and that the form she was trying to pressurise me into signing would be worthless if she didn't let me read the insert, as it would not be informed consent.
she let me have the leaflet, but didn't know the answers to the questions I had

so I am not particularly surprised that more parents don't read the inserts, tbh. I doubt lots of them are given the inserts to read...