WCS22 Physiology Of Lactation, Breast Feeding And Infant Feeding 2

Question 1

Normal newborn parameters

Answer 1

Term (37-42 week postmenstrual age):

1. Birth weight:
   <37 week: Premature baby
   37 week: 2.8 kg
   40 week: 3.4 kg (male), 3.2 kg (female)
2. Body length: 48-53 cm
3. Head circumference: 33-37 cm

Prematurity and Growth parameters:
- AGA (Appropriate for Gestational Age): 10-90%
- SGA (Small for Gestational Age): <10% symmetrical / asymmetrical
- LGA (Large for Gestational Age): >90%

Low birth weight: <2.5 kg

Average birth weight of premature delivery:
- 28 weeks: 1.1 kg
- 32 weeks: 1.8 kg
- 34 weeks: 2.2 kg

Question 2

Fluid requirement and body weight

Answer 2

Postnatal weight loss of up to **7% of birth weight due to **fluid loss

Start gaining weight from day ***5-7

Day 1: 60 ml/kg/day
Day 2: 90 ml/kg/day
Day 7 onwards: 150-180 ml/kg/day

Question 3

Developmental maturation in utero

Answer 3

• Fetal swallowing as early as 11 weeks
• GIT anatomically complete by 24 weeks
• Peristalsis at 28 weeks
• Coordinated suckling and swallowing at 33-36 weeks
• Functional development continues into infancy - Digestion + Absorption

SpC OG:
Digestion:
- Lactase induction after birth
- Protein digestion efficient
- Fat - malabsorb 10-30% fat in preterm infants

Question 4

Goal of nutritional support

Answer 4

1. Achieve appropriate growth and development
2. Compensate additional demand during disease state
3. Prevent complications of nutritional deficiency / excess

Question 5

Measuring growth standards in Chinese children

Answer 5

Growth charts

Which one to use?
- Local growth charts were derived from population with mixed feeding regimens e.g. formula, breast etc.
- WHO formulated a standard growth chart from solely breast fed infants from a healthy cohort

Question 6

Nutritional requirement

Answer 6

1. Energy
   - basal metabolic rate
   - activity
   - thermoregulation
   - costs of digestion and metabolism
   - energy loss by fecal, urine
   - heat loss by radiation and evaporation
2. Protein
   - growth
   - human milk adequate for normal term infants (2-2.5 g/kg/day)
   - but **NOT adequate for preterm (3.5-4 g/kg/day)
   - **Essential amino acids (in ***whey component of human milk)
3. Fat
   - **40-52% of total caloric intake
   - >=3% of total calories as Linoleic acid
   - **LC-PUFA important for growth / development of Retina + Brain
   —> n-3, n-6 essential fatty acid (LA, DHA, ARA)
4. Carbohydrates
   - glycogen stored from start of 2nd trimester
   - storage exhausted within 12-24 hours
   - normal glucose utilisation rate in term infant = 4-6 mg/kg/min
5. Minerals
   - Ca
   - Fe
6. Vitamins
   - ***Vit D
7. Water

Question 7

Casein and Whey

Answer 7

Casein micelles
- complexes of proteins + salts
- 20-40% of proteins in human milk
- 80% in bovine milk
- acidification —> precipitates

***Whey proteins
- portion that remains soluble on acidification
—> α-Lactalbumin
—> Lactoferrin
—> Immunoproteins
—> Enzymes (lipase, lyzozyme)

Question 8

Daily requirements in diseases

Answer 8

Respiratory distress syndrome (RDS)
- Water: ↓
- Energy: ↑
- CHO: ↑
- Protein: —
- Fat: —

Chronic lung disease (CLD)
- Water: ↓
- Energy: ↑↑
- CHO: ↓
- Protein: ↑
- Fat: ↑

Cyanotic heart disease
- Water: —
- Energy: ↑
- CHO: ↑
- Protein: ↑
- Fat: ↑

Heart failure
- Water: ↓
- Energy: ↑↑
- CHO: ↑
- Protein: ↑
- Fat: ↑

Sepsis
- Water: ↑
- Energy: ↑↑
- CHO: ↑
- Protein: ↑↑
- Fat: —

Necrotising enterocolitis (NEC)
- Water: ↑
- Energy: ↑↑
- CHO: ↑
- Protein: ↑
- Fat: ↑↑

IUGR
- Water: ↑
- Energy: ↑
- CHO: ↑
- Protein: ↑
- Fat: ↑

Question 9

Breast is best

Answer 9

1. Provide optimal source of nutrition
   - **Composition + **Volume adjusted to meeting growing need of individual infants
   - premature delivery —> high conc. of **Fat + **Protein
   - Fat conc. ↑ during an individual feeding
   - change of content as baby grows
   - formula can only gear to infants with highest possible needs —> **metabolic excess
   - Growth velocity, Protein and Fat accretion —> **Highest at birth and ↓ with age
2. Unique immunologic protection
   - matches with sequence of postnatal development of immune system
   - help adaptation of GI tract in switch from fetal to postnatal life
   - 3 overlapping groups of bioactive agents
   —> **Direct acting antimicrobial agents (against infection)
   —> **Anti-inflammatory agents (against inflammation)
   —> **Immunomodulating agents (against atopy)
   —> little known about how bioactive agents produce effects
   —> interactions between defence agents in human milk?
   —> dynamic changes in immune systems of infants and mother?
   —> simple addition of one component to formula unlikely to achieve real health benefits
   - Reduce risk of illness: **GE, respiratory, UTI, etc.
   - Long term protection against respiratory tract, GI infection, sudden infant death, obesity, CVS risk factors
   - ***Higher intelligence

Question 10

***Human milk vs Cow’s milk

Answer 10

More:
- Whey
- Vit A
- Vit C
- Vit E
- Lactoalbumin
- Lactoferrin
- IgA

Less:
- Vit B1, B2, B6, B12
- Vit D
- Vit K
- Fe (but is in much more absorbable form)
- Ca, PO4 (more in Cow’s milk but much lower absoption)
- Lactoglobulin

Question 11

Bioactive factors in human milk

Answer 11

Antimicrobial agents
1. **Lactoferrin (Fe chelation, bacterial killing)
2. **Lysozyme (bacterial cell wall)
3. ***Secretory IgA (bacterial adherence sites, toxins)
4. Antimicrobial Mucin (S-fimbriated E coli)
5. Lactadherin (Rotavirus)
6. Oligosaccharides (enteric / respiratory pathogens)

Anti-inflammatory agents
1. Growth factors, EGF, TGF
2. Enzymes that degrade mediators (Platelet activating factor - acetylhydrolase, glutathione peroxidase)
3. Uric acid, Vit A, E, C
4. Cortisol
5. PGE2
6. Modulators of leukocytes (e.g. IL-10)

Immunomodulating agents
1. β-Casomorphin
2. Prolactin
3. α-Tocophrerol
4. Cytokines
5. Nucleotides

Question 12

***Growth and nutrition of preterm infant

Answer 12

Achieve intrauterine growth rate (15-20 g/kg/day)

Preterm infant:
1. **↑ Energy expenditure
- temp loss, digestion, stress
2. **Disease conditions
- PDA, RDS
3. Low intake of protein and energy
4. Fecal loss

Problem:
1. **Highest growth needs
2. **Immature gut
3. ***Immature immune system
4. High risk of infection

Breastfeeding:
1. Prevention of NEC (Necrotising enterocolitis)
2. Improve feeding tolerance
3. Cognitive development
4. Mother infant bonding

Question 13

Growth retardation

Answer 13

Failure of normal fetal growth caused by multiple adverse effects on the fetus / premature baby

Question 14

Preterm formula

Answer 14

• ***Whey / Casein = 60:40
• Higher protein content
• ***MCT
• Ca / PO4 ratio ↑
• Higher Vit contents
• ***Less lactose
• Calorie 20-224 Cal/oz

Question 15

Improve feeding tolerance:
Human milk as ***Minimal Enteral Nutrition (Trophic feeding)

Answer 15

Minimal Enteral Nutrition (Trophic feeding):
- feedings given at small volumes to stimulate development of the immature gastrointestinal (GI) tract

Advantages:
1. Help **maturation + adaption of premature GI tract
2. **Full enteral feeding achieved earlier than formula milk
3. Mothers who initiate lactation earlier are more likely to sustain
4. Psychological well-being of mothers (bonding)

Question 16

Additives in Infant formula

Answer 16

• Lack all bioactive factors
• Lack evidence on long term health benefits

Question 17

Colostrum

Answer 17

First form of milk produced by the mammary glands immediately following delivery of the newborn, comes in **small volumes
- **Yellow to orange in color
- **Thick + sticky
- **Low in volume (suits baby’s small stomach) but **high in concentrated nutrition
- **Low in fat; **high in carbohydrate (to prevent hypoglycaemia) and protein
- **Large amount of immune factors (antibodies, secretory IgA; leukocytes, protective white cell) —> called “liquid gold”
- **Extremely easy to digest
- **Laxative effect and helps baby pass early stools (early meconium)

First 24 hours:
- 2-10 ml per feed
- 30-40 ml/day

2nd 24 hours:
- 7-15 ml per feed
- 70-80 ml/day

3rd 24 hours (milk start to come in):
- 15-30 ml per feed

Day 5:
- 500 ml/day

1 month:
- 750-1000 ml/day

Benefits:
1. Containing all necessary nutrients
2. Protects against infection
3. ***Laxative effect

Question 18

Solution to decline in breastfeeding

Answer 18

1. WHO international code and national legislation on marketing of breastmilk substitutes
2. WHO/UNICEF 10 steps to successful breastfeeding to solve poor hospital practices

Question 19

***Feedback Inhibitor of Lactation

Answer 19

Milk contains a small whey protein: Feedback Inhibitor of Lactation (FIL)
—> -ve feedback to Acini cell
—> slow milk synthesis when milk accumulates in the breast (and more FIL is present)
—> speeds up when the breast is emptier (and less FIL is present)
—> more often and effectively your baby nurses, the more milk you will make

Ensure plentiful breast milk production:
1. Remove milk from breast efficiently (every 3-4 hours)
2. More suckling from baby increase prolactin production

Question 20

***Imbalance of fore-hind milk

Answer 20

Foremilk:
- Mainly **low-fat milk
- **Higher in volume
- More watery

Hindmilk:
- More **fat globules
- **Lower in volume
- More ***nutrient rich

Excessive foremilk:
- more water soluble constituents such as lactose then fat
—> **excess lactose —> loose, frothy, green stools + symptoms of **Colic
—> **low fat intake —> inadequate intake of **fat-soluble vitamins

Solution:
Ensure babies are allowed to empty one breast first before offered another

Question 21

Insufficient milk

Answer 21

2 causes:
1. Ineffective attachment
2. Infrequent feeding

Consequences of ineffective attachment (1, 2—>4):
1. Pain and damage to nipples —> soreness, cracks, engorgement, stasis
2. Breastmilk not removed effectively —> engorgement, stasis, unsatisfied baby, wants to feed often
3. Apparent poor milk supply —> frustrated baby, refuse to suckle
4. Breast milk production declines —> baby fails to gain weight

Question 22

Causes of infrequent feeding

Answer 22

1. Delayed first feed
2. Misunderstanding about demand feeding
3. Supplements
4. Separation of mother and baby
5. Pacifiers
6. Lack of support

Question 23

Doctor’s role

Answer 23

1. Encourage skin contact and early feeding after delivery: Kangaroo care
2. Value colostrum
3. Avoid unnecessary supplements
4. Keep mother and baby together
5. Encourage frequent feeding
6. Discourage pacifiers
7. Prescribe medications with care
8. Supportive and encouraging

Question 24

Counter-regulatory response in hypoglycaemia

Answer 24

If babies are healthy, term, breastfed but sleepy (hypoglycaemia)
—> will not develop symptoms of hypoglycaemia
—> ∵ Counter-regulatory response

1. Inhibit insulin secretion
2. Breakdown glycogen reserves
3. Synthesise glucose from substrate in liver
4. Generate alternative fuel e.g. ketone bodies

Caring for healthy, term, sleepy babies
1. Skin contact and early feed
2. Frequent, extended access to breast
3. Express and give colostrum
4. Frequent observation
5. Examination to exclude underlying illness

Question 25

“At risk” babies

Answer 25

1. ***Preterm
2. ***Small for gestational age
3. ***Compromised (e.g. hypothermia, birth asphyxia (deprived of oxygen), illness)
4. Maternal diabetes
5. Maternal beta-blocker therapy

Consequences:
**Impaired counter-regulatory response
—> at risk of **neurological impairment if hypoglycaemia for long period
—> cannot rely on demand-feed

Caring for “at risk” babies:
1. Skin contact and early feed
2. Feed regularly
3. **Keep warm
4. **Monitor vital signs
5. ***Blood glucose estimations
6. Express and give colostrum

Question 26

Feeding and Jaundice

Answer 26

Vicious cycle

Reduced milk intake —> Fewer calories —> Less energy
1. **Reduced gut motility
—> **Re-absorption of bilirubin
—> Jaundice
—> Lethargy

2. Lethargy
   —> Inefficient feeds
   —> Reduced breastmilk supply
   —> Reduced milk intake

Caring for jaundiced babies
1. Keep mother and baby together
2. Feed frequently
3. Refer for extra help with breastfeeding
4. Express breastmilk and give if necessary
5. Avoid water

Question 27

Weight loss

Answer 27

Babies commonly lose up to 7% of birth weight in first **3 days (pass meconium + remove extra body fluid)
- **Upper limit: 10%
- ***Preterm baby: 15%

Start gaining weight from day ***5-7

Causes of excessive weight loss / poor weight gain:
1. Ineffective attachment
2. Infrequent / restricted feeding
3. Underlying illness

SpC OG:
1. Breastfeeding problems
2. Poor quality of suck
3. Poor feeding interactions
4. Inadequate number of feedings
5. Incorrect formula preparation
6. Neglect
7. Birth defects that affect the baby’s ability to feed (e.g. unnoticed cleft palate)
8. Medical problems that affect:
- Mouth / throat
- Absorption of nutrients
- Increase the number of calories needed (congenital heart disease)
- Gastroesophageal reflux

Question 28

Signs of ineffective milk transfer in the first few days

Answer 28

Reliable:
- **Weight
- **Stools (amount (1 poop + 1 wee in first day) + colour (get lighter in colour if enough feed))
- ***Urine
- History of ineffective feeding

***Unreliable:
- Dry skin and mouth
- Sunken fontanelle
- Sodium levels (in first few days)
- Unsettled baby

Question 29

Managing excessive early weight loss (>10%)

Answer 29

1. Exclude underlying illness
2. Refer for skilled help with attachment
3. Keep mother and baby together
4. Frequent feeding - monitor and record
5. Express breastmilk
6. Stools and urine - monitor and record
7. Monitor weight

Question 30

UNICEF UK baby friendly initiative

Answer 30

Role of paediatrician:
- Ensure safety
- Protect breastfeeding

Question 31

***WHO/UNICEF recommendation on Breastfeeding

Answer 31

First 6 months:
- Initiate within **1st hour
- Exclusive BF for **6 months
- **On-demand
- **No pacifiers
- If not exclusive BF —> suitable breastmilk substitutes e.g. infant formula

Around 6 months:
- more energy / nutrients needed that can be provided by breastmilk alone
- start eating safe and adequate **complimentary food (weaning)
- continue BF for up to **2 years and beyond (∵ immune system not well developed until 2 yo)

Question 32

Situations when exclusive BF may not be feasible

Answer 32

1. Breast milk not available
2. Inappropriate due to specific medical conditions
   - baby need special formula (e.g. intolerance, allergy, inborn errors of metabolism etc.)
   - mother taking medications CI for BF (e.g. chemotherapy)
   - mother is HIV-positive
   - mother has breast cancer
3. Mother unable to BF
4. Mother made informed decision not to BF

Question 33

***Bottle feeding - Infant formula

Answer 33

Standard vs Preterm vs Discharge (enriched) formula

Choice of infant formula should be based on infants’ medical indications

1. Infant formula milk
   - Cow’s protein formula

• Soy formula (low fat, Ca, ***lactose free, NOT suitable for preterm, NOT reduce allergy)
• Lactose free formula
• Hydrolysed formula
  —> Partially hydrolysed (prevention of cow’s milk protein allergy with positive family history, NO role in treatment)
  —> Extensively hydrolysed (treatment of cow’s milk protein allergy, malabsorption)
• Amino acid formula (treatment of cow’s milk protein allergy)
• Renal formula
• MCT enriched formula

2. Goat’s milk
3. Cow’s milk
   - Cow’s milk allergy
   —> IgE / non-IgE mediated
   —> recommend breastfeeding if strong history
   —> treatment: Extensively hydrolysed formula / **Amino acid formula
   —> NOT Partially hydrolysed formula (for prevention only) / Soy formula (*cross reactivity)
4. Evaporated milk
5. Skimmed milk

Question 34

Nutritional composition of infant formula

Answer 34

1 Energy + 33 Essential nutrients
- CHO
- protein
- fat
- ***linoleic acid
- vitamin
- minerals
- other substances (e.g. choline, myoinositol, L-carnitine)

Question 35

***Indication to choose between different infant formula

Answer 35

1. Term vs Preterm
   - Term —> Standard formula
   - Preterm (<34 weeks / BW >2kg) —> Preterm formula (**MCT, **LC-PUFA etc.)
   —> ***breastmilk fortification (with human milk / formula fortifiers) to optimise protein content
   - Former preterm —> Enriched formula
2. GI intolerance / Malabsorption
   - Normal GI tract —> Standard formula
   - Lactose intolerance (primary / secondary) —> **Lactose-free formula
   - Malabsorption / Intractable diarrhoea / Steatorrhea —> **Hydrolysed formula with MCT
   - Fat malabsorption / Chylothorax / Lymphatic disorder / Short gut —> ***MCT-enriched formula (reduced LCT for LCT oxidation defects)
3. Impaired renal / liver function
   - Chronic renal failure / Persistent hypercalcaemia —> **Renal formula (low in Ca, PO4, K, Fe)
   - Cholestasis —> MCT-enriched formula
   —> **MCT directly absorbed and to liver for rapid oxidation, bile acid not required
   —> but need ***Vitamin supplementation (ADEK)
4. Cow’s milk protein allergy (CMPA)
   - ***Extensively hydrolysed formula (cow’s milk protein hydrolysate, lactose free, bitter)
   - Amino acid based formula (free a.a., lactose free, high cost)
   - Unsuitable: Soy-based (cross-reactivity), Partially hydrolysed (prevention only), Goat’s milk (cross-reactivity)
5. Inborn errors of metabolism (IEM)
   - Upstream product: accumulated —> need to enhance excretion
   - Downstream product: deficient —> need supplement
   - Cofactors of enzyme: deficiency —> may be supplemented to enhance enzyme activity

Question 36

Examples of IEM

Answer 36

1. Defects in Amino Acid metabolism
   - Maple syrup disease (MSUD)
   - Argininosuccinic acidaemia (ASA)
   - Homocytinuria
2. Urea cycle / waste nitrogen defects —> Protein-restricted formula + Essential a.a. supplements
   - Proximal defects (NAGS, CPS, OTC)
   —> **Citrulline supplement (help incorporate nitrogen from aspartate into cycles and cleared as urea)
   - Distal defects (ASS, ASL)
   —> **Arginine supplement
3. Galactossaemia —> **Lactose-free / Soy-based formula
   - Breastmilk / Standard formula **contraindicated
4. Fatty acid oxidation defect —> MCT-enriched formula
5. Defect in organic acid metabolism —> Amino acid based formula

Question 37

Safe steps to prepare infant formula feed

Answer 37

1. ***Boil water
2. Clean working surface and ***wash hands
3. Prepare and take out ***sterilised bottle and utensils
4. Fill feeding bottle with correct amount of hot water ***>=70oC
5. Add correct amount of powdered infant formula
6. Gently shake bottle
7. Cool the feed
8. Test the temperature (***Lukewarm)

Question 38

Complementary feeding

Answer 38

Fills the gaps when BM alone insufficient to meet infants’ need
—> grow older
—> food quantity increases
—> stop growing if gap not filled

Foot types:
- specially prepared food
- family food

When:
- by **6 months (determined by developmental growth and nutritional requirements)
- too early (<4 months): unproven benefit, risk of aspiration, obesity, islet cell Ab development
- too late (>6 months): poor weight gain, risk of atopic disease, islet cell Ab development, childhood adiposity (formula-fed infants), **Fe deficiency (BF-infants), delayed oromotor function, solid food aversion

How:
- start with only 1 food item
- gradual increase in consistency and variety
- 6 months: puréed, mashed and semi-solid food
- 8 months: finger foods, self-feeding
- 12 months: similar food as family members, more mature self-feeding
- By 2 years, BM is replaced entirely by family food

Feeding patterns:
- 6-8 months: 2-3 times / day
- 9-24 months: 3-4 times / day
- additional nutritious snacks 1-2 times / day (12-24 months)

Alternative approaches:
- Baby-led weaning
- Baby-led introduction to solids

Question 39

Do’s and Don’ts in complementary feeding

Answer 39

Do:
- introduce 1 new item every few days
- mix cereal with breastmilk, formula / water in thin texture first
- feed with spoon not bottle

Don’t:
- add salt / sugar
- whole cow’s milk, hard / round food, honey (risk of botulism poisoning)
- low nutritional drinks e.g. coffee, sugary beverage, juice

Question 40

Effect of complimentary feeding on health outcomes

Answer 40

1. Growth and body composition
2. Neurodevelopment
3. Establishment and composition of gut microbiota
4. Immune-system related disorder and infections
   - infections
   - allergy
   - Celiac disease
   - Type 1 DM
   - CVS diseases