In our collective, massive experience, we have no awareness of even a single case of a woman who wished to breast feed and could not as a result of having had a nipple piercing. The milk ducts are a multiplicity of little pore-like ducts. Therefore, the likelihood of closing them all off from a piercing of usual size is virtually nil.
Most women do remove their jewelry for breast feeding and we believe this to be appropriate. As a result, some milk may come from the site of the piercing during nursing, which is not harmful nor problematic. Some will use an insertion taper (a tool designed for this purpose) to facilitate reinsertion or to check regularly and make certain the holes are open.
There is no special care that is required during pregnancy for healed piercings.
Piercings should be removed during breastfeeding as the jewelry can be a choking hazard to infants.
It is advisable to refrain from undergoing any and all body art procedures during a pregnancy, even just an ear lobe stretch. It is best to let your body focus on the important, complex and demanding task that it is handling already.
We do no perform any piercings on pregnant people as it is unlawful to do so deemed by the State of Kansas.