Human milking is the process of expressing breast milk from the human body. This practice has diverse applications, from infant feeding to managing maternal health, and is supported by scientific understanding.
The Biology of Human Milk Production
Lactation involves a complex interplay of hormones that prepare the body and initiate milk production. Early in pregnancy, prolactin begins to be produced, though high levels of other pregnancy hormones like estrogen and progesterone initially suppress its full effect. As pregnancy progresses, the body prepares for lactation by increasing milk ducts in the breasts. Around midway through pregnancy, colostrum, the first milk for the baby, starts to be produced.
Milk production is divided into stages known as lactogenesis. Stage I lactogenesis, or secretory initiation, begins around the 16th week of pregnancy and continues until a few days after birth. During this period, mammary glands differentiate into secretory cells, and small amounts of colostrum can be produced. Stage II lactogenesis, or secretory activation, starts shortly after childbirth. This stage is triggered by the rapid drop in progesterone levels following placenta delivery, allowing prolactin to become the dominant hormone and significantly increasing milk production.
Once milk production intensifies, the body shifts to a supply-and-demand system, known as galactopoiesis, to maintain supply. When the nipple is stimulated, either by an infant suckling or a pump, nerve impulses are sent to the brain, activating the pituitary gland. This releases prolactin, signaling alveolar cells to produce milk, and oxytocin, causing muscle contractions around the alveoli to push milk through the ducts and out of the nipple, a process known as the “let-down” reflex.
Methods of Milk Expression
Human milk can be expressed through several methods, each offering different benefits and levels of efficiency. Hand expression involves using the hands to gently compress breast tissue to release milk. This method is useful for initiating milk flow, relieving engorgement, or when a pump is unavailable. It can also be effective for colostrum collection in the first few days postpartum.
Breast pumps offer another way to express milk and come in various types. Manual breast pumps are hand-operated devices that use a lever to create suction, providing a portable and often quieter option for occasional use. Electric breast pumps, which can be single or double, use an electric motor to create suction and are generally more efficient for regular expression. Double electric pumps allow for simultaneous expression from both breasts, which can save time and potentially increase milk output.
Hospital-grade electric pumps are designed for heavy-duty, multi-user situations and offer stronger, more consistent suction, making them suitable for establishing a milk supply or for individuals with specific medical needs. Wearable breast pumps offer a hands-free and discreet way to express milk, allowing individuals to move around while pumping. Each type of pump varies in cost, portability, comfort, and the level of suction and cycling patterns they provide.
Common Reasons for Human Milking
Individuals express human milk for various reasons, often driven by infant needs, parent circumstances, or medical considerations. A primary reason is to provide milk for infants unable to feed directly from the breast. This includes premature babies who may not have developed effective suckling coordination, or infants with medical conditions that make direct feeding challenging. Expressed milk ensures these infants still receive the nutritional and immunological benefits of human milk.
Another common scenario involves parents returning to work or school, where direct feeding may not be feasible throughout the day. Expressing milk allows caregivers to maintain their milk supply and provide milk for their child while they are separated. This supports continued human milk feeding even when direct breastfeeding is not possible.
Milk donation to human milk banks is also a significant reason for expression. Donated milk is often pasteurized and provided to vulnerable infants, such as those who are premature or have compromised immune systems, when their own parent’s milk is unavailable. This practice provides a safe and regulated source of human milk for those in medical need.
Expressing milk can also manage various maternal medical conditions. It can help relieve engorgement, where breasts become overly full and painful. Expression can also be part of the treatment plan for mastitis, by helping to clear blocked milk ducts. Some individuals may also choose to express milk for personal preference or to build a stash for future use.
Safe Handling and Storage of Human Milk
Proper hygiene is important when handling human milk to prevent contamination. Before expressing milk, hands should be thoroughly washed with soap and water. All pump parts and collection containers that contact milk must be cleaned and sterilized according to manufacturer guidelines. Using clean, food-grade containers is recommended for collecting and storing expressed milk.
Expressed human milk has specific storage guidelines to maintain its safety and nutritional integrity. At room temperature, freshly expressed milk can be safely stored for up to four hours. For refrigeration, milk can be stored for up to four days at 40°F (4°C) or colder.
For longer storage, freezing is an option. Milk can be stored for about two weeks in a refrigerator’s freezer compartment, up to six months in a freezer with a separate door, and six to twelve months in a deep freezer at 0°F (-18°C) or colder. When thawing frozen milk, do so slowly in the refrigerator overnight, or by holding the container under cool or lukewarm running water. Thawed milk should not be refrozen and should be used within 24 hours if thawed in the refrigerator, or within one to two hours if thawed under running water.