I have to say in my experience as an obstetric nurse for 17 years, the IV
fluids that we administer to moms is indeed significant because it causes
"third-spacing", or generalized edema.  Our patients walk into the labor
suite already anticipating and requesting an epidural.  The anesthesiologists
want 2 liters of IV fluid given quickly before they even start the epidural
to prevent hypotension.  Then comes the hours of pitocin and IV fluids,
numerous epidural "top-offs" and more fluid boluses, etc, etc.

So, I see a mom who walked into the hospital with protuberant nipples, now
postpartum with much flatter nipples, impeding latch-on.  This edema can take
up to 3 days to mobilize out.  Just another example of high-tech obstetrics.

Stacey Richards RNC, IBCLC
NYC