For the past three nights our baby (who was born 7 weeks early, so is actually only 16 weeks corrected) has been waking up to 4 times during the night.

In the past he used to sleep at 7pm then up once or twice a night. Last night he went to bed at 6.30pm then woke at 8pm, 11pm, 2.30am, 4.30am then finally 6.30am. He fed each time - but not ravenously - but was very sleepy so was put back to bed straight after.

Our first baby never had any growth spurts, never clustser fed etc. Is this a growth spurt, or has it become a habit (or are they too young to form these habits?) - and should I be feeding him each time? I tried to see if he would self-settle but the crying got louder and when I went to get him, he had his eyes open.

I dont think he is ready for solids as isnt showing any ready signs?

With a toddler thats a terrible sleeper and a baby that wakes every couple of hours, its really draining me!

Yeah, I use to just go with these phases because while it's probably a growth spurt, he obviously really needs you to come to him regardless (because otherwise he'd self settle). Also I only count that as two wake ups but if you aren't use to all that night feeding it is draining - perhaps have a nice protein rich snack at around 9pm to see you through. You may find that in a week or so he you will be able to get him to resettle more quickly and a couple of those feeds will drop away.

Sounds growth spurtish to me. Could also be something like teething? I agree with 3boys, he obviously needs you so responding is probably the way to go. You could always try a cuddle first and see if that helps or send your DH in if you don't think he is genuinely hungry. Its probably too early to see if its habitual if its only happened once or twice and if he is feeding and falling back to sleep then it could be that he is quite hungry and once he's feeling full he's conking out again.

I'd definitely hold off on solids, 16 weeks is pretty young and if he isn't showing any signs there is really no point.

Also, he's not getting too hot or too cold? This time of year can be really hard to get the temp right, its warm at the beginning of the night, it can cool down a bit later.

with the waking because it is really tiring especially if its more than you are used to. We generally divide the wake ups between us once a new baby comes... I do the baby and DH does the toddler/older children (and would probably argue at times he has the rougher job, which, if all of them are waking in the night he definitely does lol) so maybe on weekends or something your DH can help out by doing the older child or something and then maybe get up with the kids in the morning so you can get some extra sleep or something?