Feeding an infant with milk produced by the breasts (see also Lactational Amenorrhea Method). Breastfeeding patterns include:

- exclusive breastfeeding Giving the infant only breast milk with no supplementation of any type—not even water— except for perhaps vitamins, minerals, or medication.
- fully breastfeeding Giving the infant breast milk almost exclusively but also water, juice, vitamins, or other nutrients infrequently.
- nearly fully breastfeeding Giving the infant some liquid or food in addition to breast milk, but more than three-fourths of feedings are breastfeeds.
- partially breastfeeding Any breastfeeding less than nearly fully breastfeeding, giving the infant more supplementation with other liquids or food. Less than three-fourths of feedings are breastfeeds.