When does baby's position become more permanent?

[PutThatInYourPipeandSmokeIt]

i.e. I am 20 weeks and baby is breech and lying obliquely along the right side (as per my scan). I know that it will move alot between now and birth etc but it has just made me wonder generally when they turn head down and when they settle in to their 'final' position.

i know a fair few people whose "breech" babies have turned as late as 34 weeks.
My first was lying transverse at 36 weeks, then went head down, then transverse, then head down again at 38 weeks I think it was.
ds2 was head down but OP from about 32/33 weeks

DD did a bunk at week 38 (having been lodged firmly in my pelvis from week 32)

She then flipped to breech and back again two days later (shortly AFTER the midwives panicked).

Generally though, by 36 weeks the head will be heavy enough to have tipped them into the right position.