Human Growth and Development

Excerpt

In the context of childhood development, growth is defined as an irreversible constant increase in size, and development is defined as growth in psychomotor capacity. Both processes are highly dependent on genetic, nutritional, and environmental factors. Evaluation of growth and development is a crucial element in the physical examination of a patient. Good working knowledge and the skills to evaluate growth and development are necessary for any patient's diagnostic workup. The early recognition of growth or developmental failure helps effective intervention in managing a patient's problem.

Stages in Human Growth and Development

1. Fetal stage: Fetal health issues can have detrimental effects on postnatal growth. One-third of neonates with intrauterine growth retardation might have curtailed postnatal growth. Good perinatal care is essential in promoting fetal health and, indirectly, postnatal growth.

2. Postnatal stage: The postnatal growth and development process happens together but at different rates. The growth occurs by discontinuous saltatory spurts with a stagnant background. There are 5 significant phases in human growth and development,

   1. Infancy (neonate and up to 1 year age)

   2. Toddler (1 to 5 years of age)

   3. Childhood (3 to 11 years old) - early childhood is from 3 to 8 years old, and middle childhood is from 9 to 11 years old.

   4. Adolescence or teenage (from 12 to 18 years old)

   5. Adulthood

Factors Affecting Growth and Development

The growth and development are positively influenced by factors like parental health and genetic composition, even before conception.

1. Genetic factors play a primary role in growth and development. The genetic factors influencing height are substantial in the adolescence phase. A large longitudinal cohort study of 7755 Dutch twin pairs has suggested that the additive genetic factors predominantly explained the phenotypic correlations across the ages for height and body mass index.

2. Fetal health has a highly influential role in achieving growth and development. Any stimulus or insult during fetal development causes developmental adaptations that permanently change the latter part of life.

3. After birth, the environmental factors may exert either a beneficial or detrimental effect on growth.

4. 1. Socioeconomic factors: Children of higher socioeconomic classes are taller than children of the same age and sex in the lower socioeconomic groups. Urbanization has positively influenced growth. The secular trend is observed in growth, where the kids grow taller and mature more rapidly than the previous generation. This secular trend is observed significantly in developed countries like North America.

   2. The family characteristics: Higher family education levels have a positive impact on growth. The inadequate emotional support and developmental stimulus, including language training, might cause deterioration in growth and development.

   3. The human-made environment influences human growth and development significantly. Ongoing studies have proven the relationship between pollutants in sexual maturation, obesity, and thyroid function. The excess lead exposure antenatally is significantly associated with low birth weight. Noise pollution due to transportation sources is also associated with reduced prenatal growth.

   4. Nutrition

   5. 1. Malnutrition plays a detrimental role in the process of growth and development.

      2. Deficiencies of trace minerals can affect growth and development. Iron deficiency usually affects psychomotor development and does not affect growth. Zinc deficiency might cause growth retardation and developmental delay. Selenium, iodine, manganese, and copper also play a significant role.

      3. Growth faltering or rapid weight gain in early childhood influences health later in life. The diet in early childhood is strongly associated with the likelihood of obesity later in life. 'Early Protein Hypothesis' shows that lowering the protein supply during infancy helps achieve normal growth and reduce obesity in early childhood. This concept of the early protein hypothesis helps improve children's food products.

5. Genetic and environmental factors influence the growth and development in a perplexing interrelated pathway. Genetic and environmental risk factors are not mutually exclusive. Plasticity is the potential of a specific genotype to bring out diversified phenotypes in response to diverse environmental factors. The developmental plasticity can happen from embryonic to adolescence and be passed on to the next generation.

6. Role of experience during early childhood: Exposure to adverse experiences might hinder development. Profound neglect during early childhood can impair development. Children adopted before 6 months of age have similar development when compared to their non-adoptive siblings. If children are adopted after 6 months, they have a high risk of cognition deficits, behavioral issues, autism, and hyperactivity. Early intervention for children with adverse experiences is the pillar of healthy development.