My sister was advised not to use one by her doctor (after she had signed up for the trial) as it can cause infection - not always but made me think twice!!! I ended up with an episiotomy as they had to use the vacuum and I won't lie - it hurt like hell for a few days but at the time I didn't even realise because of the epidural!!!! I was absolutely terrified of tearing or being cut but in the end there is not much you can do!!! good luck hun xox