Lecture 20: Lactation

Question 1

Stages of lactation? (lactogenesis)

Answer 1

Stage 1:

• Mid gestation to day 2 postpartum
• The human breast is capable of lactation from mid-gestation but lactation does not usually occur intil after partuition

The withdrawal od the placental steroids is responsible for the onset of lactation

• suckling reduces dopamine and increases VIP

Stage 2:

• PP day 3-8 starts large scale milk prdoction
• increased a-lactalbumin decreased sodium and chloride in milk (due to TJ in the alveolar epithelium)
• Galactopoiesis - maintenance of established milk secretions
• Involution - Approx 40 days after last feed - due to build up of inhibiting substances

Question 2

How does milk start out compared to mature milk later on?

Answer 2

During the first days after delivery the milk produced is a thick product call colostrum. This contains less sugar and less fat than mature milk as it it less about energy.

Colostrum contains more total protein than mature milk (esp. rich in antibodies like IgA)

Question 3

Major components of human milk?

Answer 3

I Eat Lots (of) Carbs, Lipids + Proteins With Lunch

Question 4

Does size matter?

Answer 4

The size of the breast is a reflection of the storage capacity not the production capacity. Right breast has greater production and left has greater storage capacity normally.

Question 5

Benefits of breastfeeding to the mother?

Answer 5

Mother:

• spacing of offspring as exclusive breastfeeding prolongs the duration of postpartum amenorrhea
• may also enhance weight loss after pregnancy
• bonding with offspring - eye contact
• enhances involution of the uterus
• appears to protect against TII diabetes
• May protect PP depression
• may protect against breast and ovarian cancer (esp if feeding for longer than 12months)

Question 6

Benefits of breastfeeding to the baby?

Answer 6

Baby:

• Do not tend to over-feed - leaner at 12 months
• May confer light protection from childhood obesity
• Breastfeeding conclusively reduces poor health outcomes
• Prevents exposure to diarrhoea inducing pathogens and provides protective factors (eg. antibiotics)
• protects against otitis media (particularly if fed for 4-6 months)
• protective against atopy (60% of infants that develop atopic ecsema do so within 12 months)
• In first 12months the intestinal mucosa is permeable to proteins and protective IgA system is poorly functional (IgA in milk protects infant)
• Protective against asthma
• potentially DHA enhances cognitive ability (but not well established link)
  *

Question 7

HIV transmission in breastfeeding?

Answer 7

Breastfeeding accounts for up to half of all infant human immunodeficiency virus infections worldwide and carries ann estimated transmission risk of about 15% when continued into the second year of life.

In developed countries formula feeding is a viable alternative to the cost of transmission.

Question 8

Mastitis?

Answer 8

Infection of a lactiferous lobe and appears red and often in a triangle. Bacterial infection and is not an indication to stop breastfeeding. (may actually help resolve the issue)

Question 9

Hepatitis B?

Answer 9

Proably no risk of infection but studied babies were immunised and given HbIgG so not too sure.

Question 10

Alcohol?

Answer 10

Levels of alcohol are similar in milk and maternal plasme - babies do not suckle as well after alcohol consumption.

Vodka changes the smell of milk apparently to some adult sniffers (@tommyhayes)

Alcohol may lead to a feeding problem (babies get hungover asf)

Question 11

Caffeine?

Answer 11

Readily enters milk and the baby can not process it like adults with a clearance of up to 80h compared to 3.5h

Can build up in the baby and so is NOT ok for baby

Question 12

Nicotine?

Answer 12

Found in urine of both breast and bottle fed infants

Smoking should be discouraged in everyone (which funnily enough includes women with infants)