Once you are positioned comfortably with your breast supported, and your baby is well supported and positioned with her mouth aligned with your breast, you are finally ready to help your baby latch on. Your baby's hands should be out of the way and her body pulled close to you so the breast is within easy reach. You don't want the breast pulling away from her as she tries to nurse.
Lightly touch your nipple against the midpoint of your baby's lower lip to stimulate her to open her mouth WIDE. Many women make the mistake of trying to push their nipple into their baby's mouth, just like we do with bottle-feeding. Instead of trying to insert your nipple, concentrate on bringing your baby to your breast. Lightly tickle her lip, and patiently wait until she opens very wide. Then quickly pull her toward you so she grasps your breast. A common error at this step is to attempt to latch a baby on when her mouth is not open wide enough. Usually this problem occurs because a mother is so anxious to get her baby attached that she doesn't take the time to keep tickling her baby's lower lip until she opens really wide, like a yawn. A baby who grasps the nipple without opening wide will end up grasping only the tip. Correct latch-on involves taking the entire nipple plus about one to one and a half inches of surrounding areola and breast. She must grasp sufficient areola and breast to allow her jaws to be positioned over the location of the dilated milk ducts. Since the size of the areola can vary tremendously from woman to woman, a baby may need to take it all into her mouth (if the areola is small) or may leave a margin visible beyond her lips (if the areola is large). What's important is that the baby takes the entire nipple and a large mouthful of breast. This will assure that the nipple is far back in the baby's mouth so that it won't experience any friction or pressure and, thus, won't get sore.
Latch-on can be made easier for some babies if the mother uses a C-hold and then gently compresses her fingers and thumb to make the areola more narrow. The fingers and thumb should be aligned with the baby's mouth by positioning them parallel to the infant's jaws before squeezing them together. The result is a more narrow and more protuberant areola area that may be easier for the infant to grasp properly.
When your baby is attached correctly, her jaws should be open wide, her lips flanged out, her nose resting against the upper breast, and her chin pressed against the underside of the breast. You should feel her jaws compressing the breast at a point well past the nipple. Her sucking should not be uncomfortable. The tip of her tongue might be visible between her lower lip and the breast as it lies over the lower gum. Even with her nose touching the breast, your baby can breathe comfortably because her nostrils are flared. If you attempt to press your breast away from your baby's nose, this can change the angle of the nipple in your baby's mouth, creating friction and soreness. If her breathing seems obstructed by your breast, try pulling her lower body closer to you.