Baby refusing to feed as much as before

[N4R]

My nearly 4 months old baby used to take 120-150ml of bottle per feed. However, for the last month of so, she would stop at 90ml of, pushes the teat out with her tongue and spitting the milk. We tried encouraging her after 30mins but the same thing happen, pushing the teat out and spitting the milk out. We feed her with size 3 teat using Dr Brown's anti-colic bottle.
She has always been quite a gassy baby suffering from colic and also silent reflux. We have changed multiple different formula, from aptamil, to aptamil comfort, aptamil anti-reflux, kendamil organic, SMA comfort and now to SMA advance. I used to breastfeed and also give express breastmilk from birth to 2 months old but stopped as she was having explosive green diarrhoea to the point of screaming and crying.

She salivate a lot for last 2 months but no teeth has cut through yet so I don't think is teething related.
I breastfeed my first son and we never really noticed any issues so I am not sure if this is just a common phase for a bottle feed baby?

Hi @N4R that sounds really tricky.

I wonder if the teat size is too big for baby? Babies have a suck swallow reflex initially in the early months that means as soon as a bottle is put in their mouth they drink it whether they want it or not. For lots of babies they never need bigger than a slow flow teat. Could you try sizing down to see if it helps?

Along the same lines it could be that feeding responsively and pace feeding the bottle would help (if you're not already doing that). That means following baby's lead (not on a schedule) and allowing baby to determine how much they get. It may be that baby struggles with the speed of the milk if it's not pace fed plus a fast flow teat then once the bottle is out their mouth they'd rather not start feeding again?

Four months old is a notoriously tricky age developmentally and it could be baby is just getting distracted and would rather not sit feeding?

Sorry, not sure if that's of any help at all but maybe a few things to try? A few links that may be of interest:

www.nct.org.uk/baby-toddler/feeding/practical-tips/what-bottles-and-teats-do-you-need-for-babies

www.nhs.uk/start4life/baby/feeding-your-baby/bottle-feeding/how-to-bottle-feed/feeding-on-demand/

m.youtube.com/watch?v=5hEq2QpQFT8

Hi, thank you for the response. We have always use size 3 test since she was 12 weeks old but I’ll guess downsize to try again is probably worth trying like you say.
In hindsight I now think if could be testing related as the after giving ibuprofen, she seems to feed better (3oz) roughly every 3-4 hourly but not her usual 4-5 0z.
Thanks for the link, will have a read too.

Hi, thank you for the response. We have always use size 3 test since she was 12 weeks old but I’ll guess downsize to try again is probably worth trying like you say.
In hindsight I now think if could be testing related as the after giving ibuprofen, she seems to feed better (3oz) roughly every 3-4 hourly but not her usual 4-5 0z.
Thanks for the link, will have a read too.