These extensive notes are based on the HNT 220 lecture notes and Understanding Nutrition textbook. The notes cover all the work in the module and have also been double checked using the learning outcomes in the study guide to ensure all the information was there. They also include all the necessary...
The first 1000 days
• 90% of a child’s brain develops by age 5
- At birth, the average baby’s brain is about a quarter of the size of the average adult
brain. Incredibly, it doubles in size in the first year. It keeps growing to about 80% of
adult size by age 3 and 90% nearly full grown by age 5.
- A newborn baby has all of the brain cells (neurons) they’ll have for the rest of their life,
but it’s the connections between these cells that really make the brain work. At least
one million new neural connections (synapses) are made every second, more than at
any other time in life.
Nutrition during pregnancy and lactation
Nutrition prior to pregnancy
• Achieve and maintain healthy body weight
• Choose an adequate and balanced diet
• Be physically active
• Receive regular medical care
Physiology of pregnancy
• Pregnancy begins at conception occurs approximately 14 days before next menstrual period
is scheduled to begin
• Pregnancy averaged 38 weeks in length
• Most common 40 week start counting form first day of last menstrual period
• Date of delivery: estimated time of confinement (EDC)
• Gestational age: assessment of duration of pregnancy as weeks
• Trimester 1: first 12 weeks
• Trimester 2: 13 to 26 weeks
• Trimester 3: 27 to 40 weeks
• Gravida: number of pregnancies woman has experienced
• Parity: number of previous deliveries
Introduction to growth and development during pregnancy
• A whole new life begins at conception
,• The mother’s organ systems develop rapidly (nutrition plays a very important supportive
role)
• Blood volume expand to serve as a medium to provide the foetus with energy, nutrients and
oxygen
• Total body water increases from 7 to 10 l
• Pregnant women store a significant amount of body fat to meet their own and the infant’s
energy needs and to prepare for the energy demand during lactation
• Approximately 0.5 kg of 3.5 kg of fat is deposit to foetus
Changes in mother’s body
• Blood volume expansion
• Concentrations of most vitamins and minerals in blood decrease
• Blood lipid levels increase
• Blood glucose levels increase
• Maternal organ and tissue enlargement (heart, thyroid, liver, kidneys, uterus, breasts
• Increased heart rate and decrease blood pressure in first half of pregnancy
• Increased oxygen consumption
• Increased food and volume intake
• Relaxed gastrointestinal tract muscle tone increased intestinal transit time
• Kidney changes
• Suppressed immunity
• Increased basal metabolic rate in second half of pregnancy and increased body temperature
• Hormone secretion from placenta
Maternal nutrient metabolism
• Carbohydrate metabolism
- Availability of glucose to the foetus: glucose is foetus’ preferred fuel
- Maternal insulin resistance is promoted referred to as diabetogenic effect of pregnancy
results in making mom slightly carbohydrate intolerant in third trimester of pregnancy
• Protein metabolism
- Nitrogen and protein needed for synthesis of new maternal and foetal tissues
(approximately 925 g of protein is accumulated during pregnancy)
• Accelerating fasting metabolism
, - Glucogenic amino acid utilization (amino acids that can be converted into glucose), fat
oxidation and increased production of ketones enables mom to use primarily stored fat
for energy while sparing glucose and amino acids for foetal use
• Fat metabolism
- Changes in lipid metabolism for energy needs promote the accumulation of maternal
fat stores in the first half of pregnancy and enhance fat mobilization in the second half
• Mineral metabolism
- Ca metabolism
- Characterized by increased rate of bone turnover and reformation
- Elevated levels of body water and tissue synthesis leads to increased need for
sodium and other minerals
Placental development
• Placenta produces hormones namely steroid hormones (progesterone and oestrogen) to
maintain pregnancy and prepare the breasts for lactation
• Spongy structure and develops in the uterus
• Develops as an interweaving of foetal and maternal blood vessels: maternal blood transfers
oxygen and nutrients to the foetus’s blood and picks up foetal waste products
• Uses energy (30 40% of glucose from mother) and nutrients to support its work
• A healthy placenta is essential for the developing foetus to maintain and attain its full
potential
• Foetus receives small amounts of water and other nutrients from ingestion of amniotic fluid
(fluid that contained in the amniotic sac that surrounds the foetus in the uterus)
Foetal growth and development
• Tissue increases during pregnancy
- T1: mainly mother
- T2: both mother and fetus
- T3: mainly foetus
• Growth rate:
- Week 25: 6 g/day
- Week 34: 40 g/day
- Week 40: 13 g/day
• Gestation period: period from conception till birth
, - Normal: 38 to 40 weeks
- Premature: < 37 weeks
- Post-term: > 42 weeks
• Neonatal period from birth to 28 days
Premature births, when:
• Multiple births
• Low weight gain of mother (< 7kg)
• High weight gain of mother (>14kg)
• Smoking
• Alcohol overconsumption
• Results: defects in lungs and kidney tissue
• Globally, premature birth is the leading cause of neonatal mortality, the second leading
cause of death for children under 5, and an important cause of disability and cognitive
impairment
• Numerous risk factors for preterm birth have been identified, including low or high
maternal age, maternal undernutrition, micronutrient deficiencies, infections,
diabetes, and hypertension
Foetal growth
• Birthweight is strongly related to the plasma (blood) volume: the greater the expansion, the
greater the size of the newborn
- LGA: large for gestational age
- SGA: small for gestational age
- LBW: low birth weight < 2500 g
- Intrauterine growth retardation (IUGR): low weight for gestational age determined by
size of gestational age using a reference standard
- VLBW: very low birth weight <1500 g
- ELBW: extremely low birth weight < 1000 g
LBW
Higher risk of LBW if the mother is:
• Malnourished
• Small placenta
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