Sleep training before 9 months

[Whoevenlikestomatoes]

For those who did it, did they have to do it again at 9, 12 and 18 months/around times with big regressions?

No, in that it never went back to 0. We've had hiccups because of development or regressions where things got a bit worse again for a little while (slightly longer to get to sleep, occasional intervention needed, more wake ups) but in the main we've never looked back. Sleep training is a bit of an ongoing process because they change all the time, but you should never have to go right back to the start again.

I agree with PP.

We didn't do cry it out or ferberising or anything. But we did do what I call sleep hygiene ie trying for "drowsy but awake" at least some of the time, not feeding to sleep during the day, aiming for routine etc

Once our baby slept through we had the odd bad week (teething etc) but never had to start from scratch. The exception is after we did a long holiday (3 weeks) in multiple places with the baby staying in our room every night again, she started waking in the night, usually once and for about an hour. We then had to do a bit of work on "training" her to go to sleep again on her own at bedtime ie picking her up and putting her down many times so that she'd fall sleep in her cot, if that makes sense!

I feel like the effort we put in at the start was worth it, though hard at the time (as using a cot and aiming to do "drowsy but awake" = many failed transfers and wakeful nights! I think mums I know who did bedsharing and generally fed do sleep got more sleep and naps than me in the first few months!)

I think all babies are different though, so some might not naturally respond so well to sleep "training"

No, just be consistent with your behaviour. There are always challenges at the sleep regressions, but they do pass in time. For us it was 10 days, then business as normal.