Inverted nipples fold inward instead of pointing out. Women with inverted nipples may have a hard time getting started with breast-feeding. A breast-feeding baby latches on more easily to a nipple when it is erect.
To determine whether you have flat or inverted nipples:
Special techniques and breast shells sometimes are recommended to prepare inverted nipples for breast-feeding. However, their effectiveness is questionable. Inverted nipples may naturally become more erect after the birth of your baby. Your health professional or a lactation consultant is usually able to help you and your baby start breast-feeding if your nipples remain inverted.
Regardless of whether you plan to breast-feed, call your health professional if you notice that your nipples have changed from looking erect to being inverted.
WebMD Medical Reference from Healthwise