8 week old is dropping weight centiles

[GeorgiaWerr677]

Born 75th centile and has steadily decreased to the 32nd centile now at 8.5 weeks. Baby has only put on 3lbs in last 10 days.

She feeds every 2-3 hours a mix of formula and breast milk through a bottle but won’t take more than about 70ml (2.5 oz) each time. Maybe once every 2 days she’ll take 100-120ml (3.5-4oz). Averages around 700ml (24.6oz) but sometimes more or less.

She often spits up and a few times a week she will vomit a lot after one feed. Gets hiccups a lot after feeding. I wind her after every 30ml.

She sleeps 6 hours at night, we have tried waking in the night to get more in her but she won’t take it, or if she does it will be 20ml maximum.

She seems happy, sleeps ok and has plenty of wet and dirty nappies but I’m concerned why she would be dropping centiles. The health visitor is aware and is coming back in a few weeks for another weight check.

Has anyone been through similar or got any ideas to try and increase her intake? Is my breast milk not giving enough nutrients?

If she is well and gaining weight overall (ie not losing it), this doesn't sound like a worrying growth trajectory. "catching down" centiles is quite common as the birth centile is determined by placental function and other factors.

50-75th to 25-50th is actually only crossing one centile "line", traditionally crossing two is the flag for concern but even then it describes a lot of well children too.

I wouldn't be too concerned if she's settled between feeds and is giving you plenty of wet & dirty nappies. Make sure you're feeding every 2-3h.
Is her poo yellow/brown? Green poo would be a sign she's not getting enough milk.
Also do you have a lot of milk? You could try expressing a little bit of foremilk before feeding her to make sure she gets enough hindmilk which is less watery and has more nutrients. Sometimes if there's a lot of milk they get too full on foremilk.
Are you giving "hungry baby" formula? Sometimes that can be bad because they're fuller and feed less often but don't get enough nutrients.
I was on a drip during labour which can mean babies take on a lot of fluid before they're born making them heavier at birth than they should be- my DD dropped from 75th to just below 50th centile which I think was because of this. She was only 50th centile for length at birth so I think 50th for weight is where she should have been anyway.
HV is aware so just keep up with the regular weight checks

Consider allergies such as CMPA also.

Agree, consider cmpa.

Do you find she's quite sleepy? Is she often falling asleep whilst feeding?