I think it really depends on your care givers and where you plan to birth as to whether you're 'high risk' or not with #4. At the hospital I went to (for all 4 bubs) they consider #4 to be high risk and their standard procedure is to put a canula in your hand during labour incase you have a retained placenta or PPH (apparently the likelihood of this happening can increase slightly when its your 4th, but its a load of crap, theres no difference at all and the risk is very similar for any birth - which is really low anyway from my understanding of it) and need to be taken to theatre to have it removed or the bleeding stopped etc. The whole idea that a specific number of pgs should be classed as higher risk is just ridiculous.

So it would certainly pay to be aware that somewhere along the line you may have to deal with varying opinions of what number pg is high risk just so you can nip it in the bud if it happens.