Infant Feeding Mechanics

How a Baby Breastfeeds

• Attachment is how the baby takes the breast into their mouth to feed.

Temporomandibular Joint (TMJ)

• The TMJ is a hinge joint between the mandible (lower jaw) and maxilla (upper jaw).
• The jaw is innervated by the trigeminal nerve (cranial nerve V).
• The TMJ's movements of the tongue, lips, and cheeks are crucial during sucking.
• Sucking expands the oral cavity for suction.

Baby Reflexes

• Rooting reflex: Turning the head and opening the mouth when something touches the cheek, bringing the tongue down and forward.
• Sucking reflex: Sucking to draw something into the mouth when something touches the palate.
• Swallowing reflex: Raising the jaw to swallow when the mouth fills with milk.

How Milk is Removed

• Cups breast with tongue.
• Lowers jaw to create a vacuum, drawing in milk.
• Presses upwards with tongue and jaw to close ducts.
• Swallows.

Suck/Swallow Pattern

• Beginning of feed: Short, rapid sucks.
• Active feeding: Long, slow, rhythmic sucking and swallowing, with pauses.
• End of feed: "Flutter sucking" with occasional swallows.

Seeing What the Baby is Getting

• Active feeding: (1:1 or 1:2 swallowing)
• Flutter sucking: (fewer swallows)

Positioning Principles

• Baby's head and body in line (with freedom to tilt head back)
• Baby held close to the mother.
• Nose placed on the nipple.
• Sustainable positioning.

Physiology of Lactation

• Lactogenesis is the initiation of milk production.
• Lactogenesis has three phases.
• The first two phases are neuroendocrine responses.
• The third phase is autocrine.
• Neuroendocrine phase: interaction between the nervous and endocrine systems.
• Autocrine phase: a cell secreting a hormone that acts on itself.

Lactogenesis I

• Lactogenesis I starts around 16 weeks of gestation with colostrum production by lactocytes.
• Prolactin, while present during pregnancy, is suppressed by increased levels of progesterone and estrogen, along with HPL and prolactin-inhibiting factor (PIF).
• Milk production is suppressed.

Colostrum Features

• Packed with protective factors.
• Concentrated nutrition.
• Intentionally small volumes.
• Laxative effect to clear the meconium.

Lactogenesis II

• Lactogenesis II is the onset of milk production.
• It occurs after the expulsion of the placenta and membranes.
• Prolactin levels increase and bond to prolactin receptors in the lactocytes.
• Skin-to-skin contact and early/regular breastfeeding inhibit PIF and stimulates prolactin.

How it Works

• Baby suckles, stimulating nerve impulses to the pituitary gland.
• The pituitary gland then releases hormones to both breasts.

Counterregulatory Compensation

• After delivery, a self-limiting decline in infant blood sugar occurs for the first 3 hours of life.
• Then, counterregulatory compensation takes over and alternative fuels are formed.
• Glycolysis, glycogenolysis, and gluconeogenesis are important processes.

Ketogenic Response

• Ketone bodies are an alternative fuel source for the brain when blood glucose is low.
• Breastfed infants display a brisk ketogenic response when blood glucose levels are low, while formula-fed infants do not.
• Early feeding of human milk/colostrum enhances gluconeogenesis.

Perils of Artificial Feeding

• Artificial supplements after birth increase insulin secretion, suppressing glucogenesis.
• They decrease glucagon secretion, reducing glycogen to glucose conversion.
• They delay natural gluconeogenesis and ketogenic processes.

Prolactin

• Triggered by suckling.
• Acts on lactocytes to make milk.
• Peaks about 90 minutes after a feed.
• Suppresses ovulation.
• Needs early and frequent stimulation for long-term effectiveness.

Biosynthesis of Milk within Alveoli

• Lactocytes/acini cells extract and synthesize milk components from the woman's blood and extracellular space.
• Water, electrolytes, and water-soluble constituents diffuse across the alveolar membrane.
• Milk is secreted into the alveolar lumen.

The Prolactin Response

• Sensory impulses from the nipple to the brain.
• Prolactin is secreted to the breasts via the bloodstream.
• Prolactin is secreted at night and suppresses ovulation.
• Milk production peaks after a feed for the next feeding cycle.

Setting Up Milk Production

• Delivery of placenta allows prolactin receptor sites to open on acini cells.
• Prolactin surges to "prime" sites for milk production.
• Receptor sites close if not primed.
• Frequent skin contact and feeding in early days enhance long-term production potential.

The Prolactin Receptor Theory

• Prolactin surges prime receptor sites.
• Expulsion of placenta opens receptor sites; unprimed sites close.
• Frequent prolactin release maximizes long-term milk supply.

Oxytocin

• Triggered by suckling and positive thoughts.
• Acts on myo-epithelial cells to eject milk.
• Largest peaks occur early in the feeding process.
• Effect may be felt as tingling.
• Basal levels are higher when the baby is near.
• Can be temporarily inhibited by stress.

The Oxytocin Reflex

• Sensory impulses from the nipple to the brain.
• Oxytocin is secreted to the breasts via the bloodstream.
• Myo-epithelial (muscle) cells contract and expel milk.
• Helpful factors include sight, sound, and smell of the baby.
• Becomes conditioned over time.
• Hindered by anxiety, stress, pain and doubt.
• Works before or during the feed to make the milk flow.

Prolactin and Oxytocin

• Work together to trigger feelings of love and mothering behavior.
• Induce calmness and a feeling of well-being.
• Enhance the mother-baby bond.

Lactogenesis III

• Lactogenesis III: autocrine regulation by supply and demand.
• Breast milk supply controlled by milk removal via autocrine or local control.
• Feedback Inhibitor of Lactation (FIL) is increasingly secreted by lactocytes as alveoli distend with milk, inhibiting lactogenesis.

The Feedback Inhibitor of Lactation (FIL)

• FIL is secreted as part of milk.
• Build-up of FIL blocks milk production.
• Removing FIL allows milk production to continue.

Reversing the Effect of FIL

• Emptying the breast removes FIL, allowing increased milk production.
• Each breast functions independently.
• Milk production slows as the baby is weaned.
• Midwives can help mothers understand this process.

Breastfeeding and Health

• Breastfeeding reduces the risk of gastroenteritis, chest infections, ear infections, urinary infections, diabetes, allergies, childhood cancers, Sudden Infant Death Syndrome (SIDS), and heart disease.

Breastfeeding Reduces the Risk Of...

• Breast cancer
• Ovarian cancer
• Hip fracture
• Heart Disease

'Instant' Protection from Infection

• Antibodies produced and sent to the breasts are incorporated into breast milk.
• This protects against inhaled and ingested pathogens.

Explore the intricate mechanics of how a baby breastfeeds, including essential reflexes and the role of the temporomandibular joint (TMJ) in facilitating the process. This quiz delves into the attachment techniques used during nursing and the suck/swallow patterns that optimize feeding.