17 - Nutrition, pregnancy and development Flashcards
What are the 3 stages of unborn baby development?
Zygote: a single, fertilized cell
Embryo: weeks 3 to 8 after fertilization
Foetus: week 9 to birth
When are the first, second and third trimesters?
First trimester - 1 - 13 weeks
Second tri - 14-27 weeks
Third tri - 28 - Birth (38-42weeks)
How many extra calories per day are needed in 2nd and 3rd trimesters?
350-450
How much protein and carbohydrate is needed in pregnancy?
1.1 gm/kg body weight/day of protein
175 grams/day minimum of carbohydrates
What are the dietary fat guidelines in pregnancy? (4)
1) Same % of calories as in non-pregnancy
2) Limit saturated fat; avoid trans fats
3) Omega-3 polyunsaturated fatty acid docosahexaenoic acid (DHA)
4) Arachidonic acid
Why are micro nutrients are important in pregnancy? (3)
1) Expand maternal blood supply
2) Growth of maternal tissues: uterus, placenta, breast, body fat
3) Growth of foetus
Which micronutrients are important in pregnancy? (9)
Folate, B12, C, A, D, Calcium, iron, zinc, sodium, iodine
1) What is the RDA of folate for pregnant women?
2) What is it required for?
3) What is deficiency associated with? (4)
1) 600 µg/day
2) cell division
3) Neural tube defects, macrocytic anaemia, foetal neurodevelopment [problems, pregnancy complications
What are 3 conditions resulting from neural tube defects associated with folate deficiency?
1) Spina bifida - vertebrae do not enclose the spinal cord - causing protrusion
2) Anencephaly - partial absence of brain tissue
3) Down syndrome
Why is macrocytic anaemia?
Blood cells do not mature
Low birth weight
Preterm
What pregnancy problems for the mother (3) are associated with folate deficiency?
Placental abruption
Preeclampsia
Spontaneous abortion
What is homocysteine re-converted into with the help of folate and vitamin B12?
Methionine
What is the RDA for iron during pregnancy?
27mg per day
What is the distribution of body iron?
RBC = 75-80%
Tissues (proteins) = 10%
Storage = 10-15%
What is 1000mg of additional iron needed for? (2)
- Expanding maternal RBC and plasma volume
- Growth of foetal-placental unit
What is maternal anaemia associated with?
- Lower cord Hb concentration
- Severe depletion of storage iron
= brain iron deficiency
What is perinatal iron deficiency caused by? (3)
and characterised by? (2)
Causes: Intrauterine growth restriction, maternal smoking, poorly controlled diabetes
Results in: Foetal hypoxia an augmented erythropoiesis (RBC production)
What developmental problems does iron deficiency cause?
- Affects growth and function of multiple organ systms
- affects immune function and temperature
- affects neurodevelopment
- postnatal iron deficiency
What does an excess of iron cause?
What must be done?
Neonatal haemochromatosis
Multiple RBC transfusions
What is a teratogen?
an agent or factor which causes malformation of an embryo e.g. alcohol
Give some consequences of alcohol during pregnancy
Fetal alcohol syndrome
Fetal alcohol effects (less severe and do not show at birth)
Immature liver
Spontaneous abortion, delivery complications, LBW, SIDS etc.
Explain the hypertensive disorders that can arise during pregnancy
- Gestational hypertension
- Preeclampsia: sudden increase in maternal blood pressure
Risk increased by deficiencies in vitamins C and E, calcium and magnesium
What is:
Prolactin
Oxytocin
Colostrum
Prolactin: milk synthesis
Oxytocin: “let down” of milk
Colostrum: first milk produced (introduces friendly bacteria)
What extra nutrients are required during breastfeeing?
Milk production requires 700-800kcal daily
Should consume 300-400kcal per day more than pre-preg for gradual weight loss
Take suppliments
What are the advantages of beastfeeding (7)
- Best quality nutrition
- nutrients more absorbable (iron calcium magnesium)
- Antibodies
- Helps in weight loss
- Suppresses ovulation
- Bonding
- Cost-efficient
What are some potential challenges in breastfeeding? (5)
- Possibly uncomfortable and needs practice
- Harmful substances passed from mother to baby
- HIV
- Mothers employment
- Social concerns
What characteristics of infants makes their nutritional needs unique?
- High energy needs per unit body weight (40-50kcal/lb) and 40-50% from fat
- immature digestive tracts and kidneys
What specific fatty acids to infants need?
- Arachidonic acid (AA)
- Docosahexaenoic acid (DHA)
Other than macro-nutrients, what are the specific nutrient needs for infants?
- Higher need for iron, vitamin D, zinc, fluoride, B12
- Vitamin K injections
- Need 2 oz fluid per lb bodyweight
