by Anne Smith, IBCLC

Mother's nipples come in many shapes and sizes. While most nipples protrude and are easy for baby to grasp, there are some variations in size and shape that make it difficult for them to nurse successfully. In order for a baby to nurse effectively, he must be able to grasp the nipple and stretch it forward and upward against the roof of his mouth. Flat or inverted nipples may make it difficult for your baby to nurse.

In women who are pregnant for the first time, it is very common for the nipple to not protrude fully. About one-third of mothers will experience some degree of inversion, but as the skin changes and becomes more elastic during pregnancy, only about ten percent will still have some inversion by the time their baby is born. The degree of inversion is likely to become less with each subsequent pregnancy.

Because your baby forms a teat not just from the nipple but also from the surrounding breast tissue, most inverted or flat nipples will not cause problems during breastfeeding. Some types of flat or inverted nipples will cause problems, however, and there are some steps you can take to help correct the problem both before and after the baby is born.

The first thing you need to do is determine whether your nipples really are flat or inverted. You can do this while you are pregnant by performing a simple "pinch" test: Hold your breast at the edge of the areola between your thumb and index finger. Press in gently but firmly about an inch behind your nipple. If your nipple protrudes, that's great. If it does not protrude or become erect, it is considered flat. If it retracts or disappears, it is truly inverted. Nipples that are severely flat or inverted will not respond to stimulation or cold by becoming erect. If you perform the pinch test and your nipples protrude, they aren't truly inverted and will probably not cause any problems when you nurse your baby.

A truly inverted nipple is caused by adhesions at the base of the nipple that bind the skin to the underlying tissue. While the skin does become more elastic during the third trimester of pregnancy in preparation for nursing, some of the cells in the nipple and areola may stay attached. Sometimes the stress of vigorous nursing will cause the adhesion to lift up rather than stretching or breaking loose, and this can cause cracks in the nipple tissue and pain for the mother.

Because the breasts function independently of each other, it is not unusual for a mother to have one flat or inverted nipple, or to have one nipple that protrudes more than the other. For the same reason, it is not unusual for a mother to produce more milk from one breast than the other. The degree of inversion varies greatly, ranging from the nipple that doesn't protrude when stimulated, but can be pulled out manually, to the severely inverted nipple that responds to compressions by disappearing completely.

How much difficulty a flat or inverted nipples presents to a nursing baby depends on the degree of inversion as well as the baby himself. If you have a strong, healthy, full-term, vigorous nurser, he may be able to draw out the nipple and dislodge the attachments with relative ease.

If you discover that your nipples are flat or inverted before your baby is born, you may want to use breast shells. These are plastic cup shaped shells that exert a constant, gentle pressure to the areola during the period of pregnancy when the skin is most elastic. They are worn inside your bra, which may need to be a size larger in order to accommodate the shell. The consistent, painless pressure exerted by the shells may help break the adhesions under the skin that keep the nipple from protruding. Begin wearing them for a few hours a day, starting in the last trimester. As you become used to them, increase the time until you are wearing them all day. You should not sleep in them. Remove them before going to bed, wash them, rinse, and air dry them overnight. Any colostrum that collects should be discarded. They should be emptied frequently and washed every day. Medela's shells come with disposable pads that absorb the leakage.

After your baby is born, you may want to wear the shells for 30 minutes before nursing in order to help draw the nipple out further. Once again, any milk that collects during usage should be discarded and not given to your baby.

The Hoffman Technique is a manual exercise that may help break adhesions at the base of the nipple that keep it inverted. Place the thumbs of both hands opposite each other at the base of the nipple and gently but firmly pull the thumbs away from each other. Do this up and down and sideways. Repeat this exercise twice a day at first, then work up to five times a day. You can do this during pregnancy to prepare your nipples, as well as after your baby is born in order to draw them out.

Gentle manual or oral stimulation of your nipples can be a part of lovemaking, and may encourage your nipples to protrude. Your partner will enjoy helping you prepare your nipples for nursing.