Nutrition through the Lifecycle - Lactation

Question 1

At which stage during pregnancy does the breast tissue change to accommodate milk production?

Answer 1

third trimester

Question 2

describe the basic anatomy of the breast

Answer 2

nipples and areola

• smooth muscle
• contain Montgomery’s tubercules

each breast has 15-20 lobes
each lobe contains a lactiferous duct

lactiferous sinuses lie at the nipple end of the lactiferous duct

Question 3

where is the site of milk production in the breast?

How is milk produced?

Answer 3

alveolar cells

layer of epithelial cells that line the alveolar lumen
milk is produced here and drains into the lactiferous duct

Question 4

Describe colostrum and explain it’s function in infant development

how much is produced per day?

Answer 4

• immature milk produced for the first 2-3 days after birth
• thick, sticky, yellow fluid
• small in quantity - 100ml/day

minimises risk of infection and maturation of the gut

Question 5

what are the components of colostrum?

Answer 5

high in protein, lactoferrin, immunoglobin A and vitamin A

low in lactose and fat

Question 6

describe transitional milk.

Answer 6

• produced from days 3-7 postpartum
• produced in larger volume
• lower protein content, higher lactose and fat content

Question 7

When is mature milk produced?

What is its nutritional content?

Answer 7

from 14 days postpartum

similar nutrient content to transitional milk

Question 8

at the peak of lactation, roughly how much milk is produced per day?

Answer 8

750-800ml milk

Question 9

what percentage of total energy does fat constitute in mature human milk?

What is the primary form of fat in mature milk?

Answer 9

50% energy comes from fat - primary form is trigylcerides

Question 10

what percentage of total energy do carbohydrates constitute in mature human milk?

what is the primary form of CHO in human milk?

Answer 10

40% of energy comes from carbohydrates - lactose is the primary form

Question 11

which proteins are primarily found in human milk?

Answer 11

casein and whey

Question 12

describe the term ‘let down’

Answer 12

the release of milk fro the breast

Question 13

describe ‘foremilk’.

Answer 13

the first milk to be released from the breast when feeding is initiated.
more watery than hindmilk - aims to quench thirst
less calorie dense as contains more lactose than fat

Question 14

describe ‘hindmilk’.

Answer 14

hindmilk is the milk released after ‘let down’ occurs.

richer and more nutrient dense than foremilk.

Question 15

describe how the composition of human milk varies throughout the day.

Answer 15

breast milk generally contains more fat in the evenings

Question 16

describe the carbohydrate content of breast milk:

what % is lactose?
what is the remaining % made of?

Answer 16

80% lactose

remaining 20% are oligosaccharides

Question 17

describe the fat content of breast milk

Answer 17

• 98% triglycerides - remaining 2% are diglycerides, monoglycerides, FFA’s, cholesterol, phospholipids
• fat is suspended in emulsified droplets

Question 18

describe the protein content of breast milk

Answer 18

• major proteins are whey and casein

- whey proteins are primarily lactoferrin and a-lactalbumin

Question 19

which two hormones are produced during breast feeding?

describe their roles.

Answer 19

• prolactin and oxytocin

prolactin initiates milk secretion
triggered by infant suckling

oxytocin triggers milk ejection
‘let down’ reflex
milk released from mammary glands to nipple to infant

Question 20

Why can’t you give water to a breastfeeding baby before 6 months?

Answer 20

• risk of diarrhoea/infection due to un-pure water
• risk of malnutrition as baby may drink less breastmilk and mother will produce less milk over time.
• breastmilk contains adequate water, especially in foremilk.

Question 21

How does maternal nutrient requirements change during lactation/breastfeeding?

How many kcal per day does breastfeeding cost?

How many extra kcal/day does mother need if breastfeeding?

Answer 21

Same as or increased from pregnancy

around 650kcal per day

330kcal per day

Question 22

How much weight roughly can a women lose per month whilst breastfeeding?

Answer 22

0.8kg per month

Question 23

how many extra calories per day does a breastfeeding woman need?
how is it calculated?

Answer 23

approximately 330kcal

calorie content of breast milk = 0.67kcal/g
approx 750-850ml breast milk produced every day

Question 24

Which vitamins/mineral requirements increase during lactation and why?

Answer 24

all but vitamin D which stays the same (10 micrograms)

zinc - plays an important role in over 300 enzymes in breastmilk and plays a role in macronutrient metabolism

Question 25

What is the vitamin D requirement for both mother and baby?

Answer 25

mother - 10 micrograms baby - supplemented with 8.5-10 micrograms from birth to 1 year old

Question 26

what are some advantages of breastfeeding for the mother?

Answer 26

- dont need to prep bottles/formula - cheaper - develop emotional bond between mother and baby - aids postpartum weight loss - oxytocin release from let down reduced anxiety - helps mother understand needs of the baby - delayed return of menstrual cycle (contraception and iron store)

Question 27

what happens to the bone health of women whilst breastfeeding and why? cue questions: how much Ca needed per day in BM? how much Ca needed in total for 6 month feeding?

Answer 27

calcium needed for breastmilk (200-225mg/day) comes from maternal store (spine and hip usually). approximately 35-40g calcium needed for 6 months breastfeeding bone mineral density decreases 4-6% however is still 3-5% higher than those who have never had a baby. BMD recovers after breastfeeding and adaptive mechanisms to preserve Ca, increase bioavailability and increase remineralisation take place.

Question 28

What are some advantages of breastfeeding for the infant?

Answer 28

- human milk remains nutritionally adequate even if mother undernourished - provides immunoprotective factors e.g., antibodies - guarantees nutrient availability for the infant is optimal - reduces risk of childhood obesity - essential for brain development - promotes development of immune system

Question 29

What are some bioactive proteins in breastmilk?

Answer 29

- iron bound to lactoferrin | - lysozyme (antimicrobial agent)

Question 30

Describe the link between breastfeeding and risk of childhood obesity.

Answer 30

childhood obesity risk is reduced by 22% in those breastfed as opposed to bottle fed

Question 31

which omega-3 fatty acid in breastmilk aids brain development? How can breastmilk levels of this nutrient be maintained?

Answer 31

DHA (Docosahexanoic acid) is a omega 3 fatty acid in human milk, DHA benefits brain growth and development mothers can supplement with fish oils to increase DHA content in breastmilk

Question 32

What signs might indicate that an infant is getting enough milk?

Answer 32

adequate weight gain good skin colour and tone urinates 6-8 times a day poos 3-4 times a day

Question 33

What does WHO recommend about the duration of breastfeeding, including feeding with colostrum?

Answer 33

feeding of colostrum should be initiated within the first hour of birth babies should be exclusively breastfed for at least 6 months from 6 months onwards they can have complementary foods breastfeeding can continue up to age 2 years

Question 34

What is the breastfeeding trend in the UK?

Answer 34

very low rates of breastfeeding by age 6 months in the UK (34%) breastfeeding especially low in young mothers and those from low socioeconomic backgrounds

Question 35

What is the WHO breastfeeding goal? what is the current status?

Answer 35

50% babies exclusively breastfed by 6 months currently, only 38% of babies are exclusively breastfed by 6 months

Question 36

What are the laws on breastfeeding in the UK and Scotland?

Answer 36

it is gender discrimination to treat a woman unfavourably if she is breastfeeding in public. Scotland have implemented the issuing of fines if women are treated unfavourably.

Question 37

What are the different types of infant formula?

Answer 37

cows milk formula soya formula hydrolysed protein and amino acid based formulas sheep/goats milk derived formula

Question 38

What happens to a mother's breastmilk if alcohol is consumed? hw long does it take to clear from milk?

Answer 38

- consuming alcohol changes the odour and taste of breastmilk - maternal plasma and breastmilk alcohol levels peak at 30-60 minutes after alcohol consumption (60-90 minutes if consumed with food) - 1 serving of wine/beer takes about 2-3 hours to clear from the milk?

Question 39

What is recommended for breastfeeding mothers who want to consume alcohol?

Answer 39

- express milk prior to drinking alcohol | - wait 2-3 hours to feed after alcohol consumption

Question 40

what are the effects of smoking on breast milk? cue questions: what happens to volume of BM?

Answer 40

smoking decreases breast milk volume | nicotine levels in breastmilk are higher than maternal plasma

Question 41

what are the effects of caffeine consumption whilst breastfeeding? what % of maternal plasma level does infant receive? how many caffeinated drinks are recommended per day?

Answer 41

caffeine passes into breastmilk and infant receives 1% of maternal plasma level infant does not develop ability to metabolise caffeine until 3-4 months so infant becomes fussy and hyperactive as caffeine builds up. 1-2 cups of coffee per day is fine

Question 42

Quickfire Questions: Does breastfeeding cost energy? Can women produce enough milk to meet the needs of multiple births? e.g triplets? When should breastfeeding start? Does breastfeeding really protect against pregnancy? Can you give unmodified cow’s milk for an infant? Does a malnourished woman provide a lower quality of milk compared to a well-nourished woman? Can women drink alcohol while breastfeeding? Do you know an example of an advert for an infant formula (0-1 year)?

Answer 42

Yes Yes ASAP - at least 1 hour after birth Yes - delays return of menstrual cycle No No - quality of milk is preserved over quantity Yes - advised to express beforehand or wait 2-3 hours after consumption