Rinnapiim

Rinnapiim is the Estonian term for breast milk, the milk produced by the mammary glands of human females. It is the natural and primary source of nutrition for newborns and is widely considered the optimal feeding choice during the first months of life. Rinnapiim supports growth and development and remains a common part of infant feeding for as long as desired by families and in many cultures.

Composition and characteristics: In the first days after birth, the mammary glands produce colostrum, a dense fluid rich in proteins, antibodies, and growth factors. As lactation continues, mature rinnapiim provides a balance of carbohydrates (lactose), fats, and proteins, along with immune components such as secretory antibodies, lactoferrin, and various enzymes. It also contains human milk oligosaccharides that support digestion and help shape the infant’s gut microbiota. The composition of rinnapiim can adapt over time and during a feeding to meet the infant’s changing needs.

Biology and feeding: Milk production occurs through a supply-and-demand process; regular breastfeeding or milk expression sustains production. Hormones such as prolactin and oxytocin regulate milk synthesis and the milk-ejection reflex. Donor rinnapiim from screened milk banks is sometimes used when a mother’s milk is unavailable or insufficient.

Health, safety, and alternatives: Breast milk provides nutrition and immune support, and is associated with reduced infection risk and other health benefits for the infant. It also offers maternal health benefits, including effects on the uterus after birth. When breastfeeding is not possible, expressed rinnapiim or medically supervised alternatives, including infant formula, may be used. Proper handling and storage of expressed milk are advised.