Pregnancy

Question 1

Physiological changes during pregnancy: GI tract, cardiac metabolism, pulmonary system, urinary system

Answer 1

• GI tract: slowed digestion and reduced gastric acid for better nutrient absorption, baby pressing on stomach can increase reflux
• cardiac metabolism: substantial increase in blood (foetus needs 625 mL/min) leads to utilisation of fatty acids as fuel and down-regulation of glucose, more efficient
• pulmonary system: 25% increase in oxygen consumption, progesterone increases pCO2 sensitivity to aid with excretion of foetal waste too
• urinary system: 30% increase in glomerular filtration rate to get rid of waste from foetus too. Also progesterone increases incontinence

Question 2

Pre-pregnancy nutrition recommendations

Answer 2

1) both mum and dad have healthy weight, which will reduce issues with sperm viability and reduce pregnancy complications
2) remove teratogenic substances from diet: alcohol, smoking
3) ensure no Zn deficiency (can impact sperm viability and associated with foetal malformation)
4) ensure supplementation with 400 mcg folic acid per day to limit NTD risk
5) remove high vitamin A compounds (supplements, liver) as teratogenic effect, can consume carotene containing compounds freely
6) be physically active
7) maintain a balanced diet with sufficient PUFA (for foetal brain and CNS development)

Question 3

Key development milestones for foetus

Answer 3

• weeks 0-8: critical development of major organs, i.e heart, brain, eyes, neural tube fusion
• weeks 9-12: ear canal, genitalia, hardening of jawbone
• weeks 13-16: ovaries and testes developed inside body
• weeks 17-20: skin development, nervous system, movements start
• weeks 24 onwards: growth and subcutaneous fat deposition

Question 4

Complications of pregnancy related to nutrition

Answer 4

• NTD defects: folic acid deficiency
• fetal alcohol syndrome (attention deficit, lower IQ): alcohol consumption
• pregnancy-related anaemia: inadequate Fe and B12 consumption
• ## fetal growth restriction due to excessive caffeine intake

Question 5

Nutritional requirements during pregnancy

Answer 5

• eatwell plate
• 5+ portions of fruit and veg a day
• 1/3 starchy food with a preference for wholegrain
• 2 protein portions per day
• 3 dairy portions per day with preference for low fat
• 1 portion of oily fish per week
• 8 glasses of water
• 10 mcg vitamin D per day to minimise impact of bone loss
• 400 mcg folic acid daily from 1 month preconception to 3 months post conception
• extra 200 kcal per day

Question 6

Foods to avoid during pregnancy

Answer 6

• undercooked eggs/ poultry due to salmonella risk
• soft and unpasteurised cheeses due to listeria risk
• shark/marlin/swordfish and limit to 4 medium cans tuna per week due to mercury poisoning (1 portion of oily fish per week)
• 200 mcg of caffeine per day (2 mugs of coffee or 3 of tea) to prevent fetal growth restriction
• liver or vitamin A supplements due to being teratogenic

Question 7

Nutritional requirements during lactation

Answer 7

• avoid alcohol, spicy foods, excessive caffeine, possible allergens
• extra 450-570 kcals/day
• eatwell plate
• increased nutrition requirements
• moderate exercise

Question 8

How nutritional status post-conception may influence outcomes of pregnancy

Answer 8

• dutch famine: 50% women amenhorrea, high incidence of low birthweight infants
• famine in first trimester may influence: NTD, birth defects, low birth weight preterm births
• famine in second and third trimesters: low birth weight infants
• the barker hypothesis: maternal environment has direct effect on the fetus and can influence DNA methylation patterns i.e IGF2, influencing obesity and later chronic disease risk