Lecture 25: Lactation Flashcards
What are the 4 stages of Lactogenesis and when
Stage 1: Mid gestation to day 2 PP: preparation stage where lactation is capable but not mature milk
Stage 2: 3-8 days PP - start of large scale milk production where there is increased a-lactalbumin and NaCl in milk due to tight junctions in alveolar epithelium
- Galactopoiesis: maintenance of established milk secretion
- Involution:
Approx 40days after last feed during weaning. This is caused by build up of inhibiting substances (^dopamine, decrease VIP)
What is colostrum, when is it produced and how does it compare to mature milk
Colostrum is produced before galactopoiesis in the first few days after delivery.
- contains less sugar and fat than mature milk
- contains more total protein than mature milk
- especially rich in IGA antibodies which provide protection against environmental pathogens
What are the 10 components of breast milk separated into those that help gut development (3,1), immunoprotection (5) and nutrition (4)
Immunoprotective
1. Phagocytes (90%), lymphocytes, T cells
- Small soluble signalling molecules -immunomodulators eg. prostaglandins, cytokines to promote leukocyte movement in the gut
- Immunoglobulins - IgA
- Lactoferrin - soaks up iron-Antibacterial and important for metabolic enzymes
- Lysozyme: antibacterial
Nutrition
6. Lactose: breaks down into glucose and galactose needed for myelin synthesis: neurodevelopment
- Lipids: triglycerides source of calories, long chain polyunsaturated FA - DHA associated with cognitive ability
- Vitamins: antioxidant
- Water: hydration (87.5%)
Gut development
2. (eg. growth factors EGF for gut growth)
- promotes growth of lactobacillus bifidus: microflora balance
- Enzymes involved in digestion: lipase (hydrolyses fat) and amylase (polysaccharides)
What are the major differences between bovine and human milk
- Humans have:
- higher lactose and fat content than cows milk
- higher lactalbumin to casein ratio (cows opposite)
- Higher linoleic acid (essential fatty acid) % in the fat
How does breast size affect the amount of milk made vs stored
Larger breast reflects greater storage capacity (more ducts, alveoli)
However it doesn’t reflect milk production capacity which is dependent on amount of prolactin and suckling.
What are the 5 public/personal health benefits of breast feeding for the mother
- Spacing of offspring:
- exclusive bf for 6mo prolongs PP amenorrhoea
- may also enhance weight loss after pregnancy - Bonding to offspring as at the level of breast, bb’s focal distance is good for eye contact
- Enhances involution of the uterus
- Appears to protect against type 2 diabetes, post partum depression,
also
5.breast cancer and ovarian cancer (12mo+ more) - lactational amenorrhoea may be contributing
What are the 8 public/personal health benefits of breast feeding for the baby
- Reduces poor outcomes of mortality and morbidity related to infectious disease by providing protective factors - IgA
- prevents exposure to diarrhoea inducing pathogens - GI tract infections
Protection against
3. Otitis media -(exclusive 4-6+mo)
- developing Atopy (eczema) - more susceptible due to intestinal mucosa permeable to allergens which are soaked up by poorly functional IgA system
- developing asthma (3mo+ exclusively) - esp with strong family history
- Obesity later in life, Diabetes 1 and 2- may due to less overfeeding?
- SIDS
Benefits
- DHA in breast milk enhances cognitive ability (however confounding factors)
What diseases are transmissible through breast milk where breastfeeding may not be advisable and which are not:
Transmissible: HIV - fatal, but in developed countries formula feeding is the alternative. Underdeveloped with dirty water can lead to rotavirus
Non transmissible/ don’t need to stop breastfeeding
- Mastitis: infection of the lactiferous lobe with a red triangle. Bacterial infection or duct blockage so good to keep breast feeding
- Hepatitis B: okay if babies were immunised and given HblgG- antiglobulin to neutralise Hep B at birth
What are three drugs/substances that are transferred in breast milk and what is ok/not ok
- Alcohol with levels similar to maternal plasma, vodka makes it smell different. Not ok as can lead to feeding problems as bb is sleepy and don’t suckle well.
- Caffeine: readily enters milk and bb has very slow clearance so can build up over a week. Normal intake is OK but excess can lead to sleeplessness, irritability of infant
- Nicotine: not ok, found in the environment of the bb and is in breast and not bottlefed infant urine.
What is the baby friendly initiative
Scheme launched in 1991 by UNICEF and WHO to promote exclusive breastfeeding in hospitals
What is the good time for exclusive breast feeding, what are the ethnic disparities and how should health professionals approach women
- 5-6 mo
- Maori, Pacific and Asian population have decreased breastfeeding compared to European. It is more common in older mothers
- Don’t make mum feel inadequate for not being able to breastfeed, no judgement but strongly encourage breastfeeding
