Susan Nachman-Srebrnick asks:
<<Does anyone know what the effect of a 24 hour fast has on lactation?
Every year before Yom Kippur, I get tons of calls from women wanting to
know if they should or shouldn't fast.  Religious issues aside, what are
the medical cons of fasting for a day?  Is it safe for a pp mother?
I'm more concerned about the fluids than I am with the food.>>

I have no research based knowledge on this, but I can give you my .02 from my
own experience and a lot of talks with others on this subject.

The two kinds of risk of not drinking all day are, Mom gets dehydrated, and,
Because of Mom's dehydration she doesn't make enough milk.

Mom's dehydration is comparatively easy to deal with -- if she feels thirsty
she needs to drink -- if you are more cautiously inclined you could say, if
her pee is startlingly yellow she needs to drink -- and the risk are pretty
low, since even if she misjudges and gets a little woozy she can sit down and
get cracking with the water pitcher and feel better pretty soon.

However, I have come to the conclusion that drop off of milk supply related to
that dehydration s a bigger issue for fasting mothers.    I DID in fact drink
on Yom Kippur when I was otherwise meant to be fasting because of this.

 The reason I think this is that on two occasions when I was bf I had food
poisoning, and spent 24 hours or a little more dehydrating myself out of
orifices on both ends -- and both times had SIGNIFICANT drop offs of milk
supply, from so overflowing as to be almost a problem to hungry baby and
nothing with the pump.   Both times a long nurseathon afterward brought my
supply back up to the point where the baby wasn't hungry -- but never again
was I able to pump (I was & am working out of the house) as easily as before,
and it was a significant problem for me.   If my supply had been a bit more
tenuous before I got sick I would almost certainly have needed to supplement.

So I urge mothers who are not ready to wean to err on the safe side, and make
sure that even if they are not eating they are drinking water, even on Yom
Kippur.

Elisheva Urbas in NYC, who with both kids now weaned is girding herself for
her first "real" Yom Kippur fast in a long time!