Breast milk and breastfeeding
The hormonal balance of oestrogen and progesterone changes during pregnancy and causes the mammary glands (the milk-producing organ in a mother’s breast) to develop. From the 16th week of pregnancy, mothers are able to produce milk from their breasts but hormones inhibit milk production until birth.
Content of breast milk
The consistency and composition of breast milk changes naturally according to the exact needs of each baby. There are differences according to the age of the infant, the time of day and the nutrition of the mother. The content also varies depending on the following three different stages of milk production (lactogenesis stages):
- Colostrum is the first fluid provided by mothers during the first days after birth. It is produced in low quantities with a relatively low concentration of fat resulting in lower nutritional quality. Therefore, it is ideal for the immature intestinal tract of newborn babies. It is highly digestible and supports the passing of meconium, the infant’s first stool. Additionally, colostrum is rich in components such as lymphocytes, antibodies, growth factors and high protein levels, which help the children to develop and to enhance their immune system.
- Transitional milk combines some of the characteristics of colostrum with those of fully mature breast milk. It is usually produced from 5 to 14 days, or even longer after birth, and supports the nutritional needs of the rapidly growing baby during that time.
- Fully mature milk is produced between 4 to 6 weeks after birth and remains almost unchanged until the end of lactation.
The main macronutrients in breast milk are lactose, fat and proteins. They may vary depending on lactation stage and among women. Fat is the most variable nutrient while lactose does not change much over different lactation stages or throughout the day. Moreover, the so-called hind milk, which is the last milk of a feed, contains more fat than foremilk, which is the initial milk of a feed. Protein concentration is higher in the first weeks after birth and decreases after 4 to 6 weeks. Proteins like immunoglobulin A are very important for the immunity of the child. In addition, human milk contains various micronutrients such as Vitamin A, B1, B2, B6, B12, D, and iodine, which also vary across women depending on their diet and body stores. They are relevant for the development and different organ functions of a newborn baby.
Benefits of mother’s own milk (MOM) and breastfeeding
Several studies have confirmed the health benefits of breastfeeding and providing newborns with their mother’s own milk. These benefits include:
- Mother’s own milk protects babies against gastrointestinal and respiratory infections.
- Breastfeeding results in reduced risk of NEC (Necrotising Enterocolitis), an acute inflammatory disease of the intestines and the most common gastrointestinal medical emergency occurring in neonates.
- Human milk also protects against pneumonia (lung inflammation) and sepsis.
- Fatty acids in breast milk are easily digested and promote faster emptying of the stomach.
- Protective enzymes, hormones and growth factors are important for intestinal growth and maturation.
- Human milk is well tolerated and digested on preterm babies and results in faster weight gain.
- Colostrum, the first fluid provided by mothers during the first days after birth, is rich in essential immunologic and developmental components.
- Lipids and fatty acids are important for neurological and visual development.
- Skin-to-skin contact during breastfeeding, also called kangaroo care, gives baby and mother a feeling of emotional closeness.
- Kangaroo care may reduce postpartum depression in the months following birth.
- Skin-to-skin contact also has a physiological effect on preterm infants such as stabilised cardiac frequency, blood oxygen, and breathing frequency.
- Breastfed babies are at lower risk of sudden infant death syndrome (SIDS).
- Breastfeeding lowers the risk of bleeding after delivery, as well as the risk of breast and ovarian cancer.
- Milk expression after a caesarean section is particularly important to help the uterus return to its normal size.
- There is a link between breastfeeding and decreased risk of overweight and obesity in adults and lower risk of type II diabetes and high blood pressure in later life.
- Some studies also reported risk reduction in breastfed children to develop clinical asthma, atopic dermatitis or eczema.