Nutrition, growth & puberty Flashcards
What are the advantages of breast feeding for the infant?
1) Provides ideal nutrition for infants in first 4-6 months of life.
2) Life-saving in developing countries - contaminated environment
3) Enhances mother/child relationship
4) Reduces risk of GI infection, and in pre-term infants (necrotising enterocolitis)
5) Reduces risk of developing insulin-dependant diabetes, hypertension and obesity in later life
Advantages in breast feeding for the mother?
1) Promoted close attachment between mother and baby
2) Helps reduce risk of premenopausal breast cancer
Potential complications of breast feeding?
1) Unknown intake - volume of feed unknown
2) Transmission of infection: HIV, Hep B, maternal CMV
3) Breast-milk jaundice - protein in milk reduces ability of liver to breakdown bilirubin - mild, self-limiting unconjugated hyperbilirubinaemia (advise continuation of breastfeeding as benefits outweigh risk)
4) Transmission of drug metabolites, alcohol, smoking to baby
5) Vitamin K deficiency - insufficient Vit K in breast milk to prevent haemorrhage disease of the new born (supplements required)
6) Nutrient inadequacies: Breast-feeding beyond 6 months without timely introduction of appropriate solids - can lead to poor weight gain and rickets
7) Logistics of breastfeeding can be difficult.
Why is it important to measure growth?
1) Measurements of growth provide sensitive indication of health in childhood, and change in growth rates can provide early and sensitive pointers to health problems.
Factors that affect growth?
1) Parental genotype and phenotype
2) Quality and duration of pregnancy
3) Nutrition
4) Psychosocial environment
5) Growth promoting hormones and factors
Drivers of growth?
Infancy: Nutrition and insulin like growth factor (IGF) are the major drivers.
Early childhood: Driven by growth hormone (from pituitary) and thyroxine
Puberty: Growth hormone and sex steroid (testosterone or oestrogen)
Assessment of growth? Reasons for unreliable measurements?
Height measurement (length measurement in babies) and head circumference
- Unreliable measurements:
1) Inaccuracy - faulty equipment/faulty technique
2) Uncooperative child
3) Different observers
4) Different times of the day
Growth charts:
- Standard UK growth charts based on height measurements of several thousand children over 10 years.
- Separate charts for boys and girls.
- Based on white UK children only (consider if child is from similar population the growth chart data is based on).
- Normal range sits two standard deviations above and below mean.
- Serial measurements give better indication of growth trend than single measurements (growth is a dynamic process).
What is a ‘target height’ when using growth charts?
Target height can be based off the ‘mid parental height’ to see if child is on or off target since they are unlikely to grow significantly taller or shorter than parents.
Formula for mid-parental height:
Boys: (FH+(MH+12.5cm))/2
Girls: (MH+(FH-12.5cm))/2
Interpreting growth:
What is the pattern of growth?
- Look at RATE (better indicator than height): Height and growth velocity.
- Everyone’s height is different but growth rate should be similar, change of more than two gentiles up or down is cause for concern.
- Fastest growth rate in utero and infancy, slows down gradually to puberty, and a significant growth spurt at puberty.
- Growth ends with fusion of the epiphyses.
Sex difference in growth?
- Growth spurt related to puberty is about 2-3 years earlier in girls than boys (girl’s taller at puberty)
- Girls have their growth plates fused earlier than boys hence their final height tends to be less.
Normal puberty sequence of boys?
1) Testicular enlargement (FIRST SIGN)
2) Pubic hair
3) Growth spurt
-Between 10-14 years, If onset before 9 - precocious, and after 14 is delayed.
Normal puberty sequence of girls?
1) Breast bud development
2) Pubic hair/growth spurt
3) Menarche
- between 8 1/2 - 12 years, onset before 8 years is precocious and after 13 years is delayed puberty.
