How does supply *work*?

[GeorginaA]

I think I'm confused and just want to check how this all works.

Last night I expressed 6oz of milk, which normally ds2 would have around 10.30/11pm ish. However, he didn't wake up for it so I froze it instead. Today he's fussy at the breast and a bit miserable, but I've checked after he's finished and I can still very easily squeeze some milk out.

Now, I'd like to be able to keep expressing in the evenings for a few days (preferably around the 6oz mark) because early next month I am visiting schools in the area for ds1 so I'll need to leave ds2 with someone, ideally with a bottle of EBM "just in case" (although timings mean chances are he won't need it). BUT - does taking this "extra" 6oz off a day mess up supply? I.e. am I going to create an artificial growth spurt scenario? (Having only just got my nights back, I REALLY don't want him to wake in the night again for a while). If I instead express every other night am I going to be able to build up my freezer storage without creating supply problems/night waking problems?

I'm confusing myself with a whole lot of ignorance over how this all works. Ds2 is 5 months old, btw.

You expressing in the evenings shouldn't affect your son's night sleeping. The more you nurse and express, the more milk your body will make.

that really is about all there is to it. Your body will make as much milk as he needs and he will take as much as he needs.

FWIW I can still squeeze a bit out and I'm only give 13mo ds2 a bedtime feed.

So there won't be a 3 day adjustment period while my body gets used to making 6oz more than requirements?

I wouldn't think so. My dd varied a lot day to day in how much she would consume, so I don't think 6oz should make a significant difference.

I know that for me, taking an extra 6oz one day would affect my supply. Usually I build up slowly to expressing that much off. 1 oz one day, 2 ounces next 3-5 days, 3 oz next 3-5 days, etc. I suspect (this is not scientific, just my experience) that your body can adjust the fluid levels easily, but not the fat levels. So fussiness could mean not as much fat in the milk as usual.