Hi Leslie,
I have heard the nipples you described as "inverted in the center" called
dimpled nipples.  I have seen a few sets of dimpled nipples in moms who
formerly had inverted nipples which had been stretched out by their first
baby.  The dimples often are permanent.  You did not say if this was a first
time mom or not.
        were the nipples flat at rest, or during a "pinch test"?  what happens
when the areola is compressed is much more important than what the nipple
looks like at rest.  It is a lot easier to get a baby to nurse when a mom has
flat or inverted nipples when that baby has not had bottles.  They still give
sugar water here in NYC too.  We have lots of work to do, don't we?
Catherine Watson Genna, IBCLC