Factors affecting child development – Growth and development is a complex process that depends on the inherent biological potential as well as various environmental influences including social, emotional and pathological factors. Important factors affecting child development are as follows —
I. Intrinsic (Biological) factors affecting child development determine the inherent pace, pattern and ultimate potential for growth & development, achievable under best environmental situations and include —
a) Age: General pace of growth is highest in intrauterine life and early infancy, decelerates gradually with advancing childhood, followed by a second growth- spurt with onset of puberty.
b) Sex: Boys are usually heavier and taller than girls in early childhood but puberty begins and completes earlier in girls.
c) Ethnicity: Caucasians and children of developed countries have better growth, due to inherent potential as well as good environmental factors e.g. good nutrition and less infections.
d) Hereditary: Children of taller parents are usually tall and vice-versa. Age of menarche in daughters usually correlates well with that in their mothers.
e) Genetic disorders are associated with inherently altered growth potential e.g. short-stature in Turner syndrome, achondroplasia etc. and tall-stature in Marfan syndrome etc.
II. Extrinsic (Organic) factors affecting child development are prime determinants of growth and development in developing countries, which directly facilitate or limit the achievement of inherent growth potential. The exact effect of these factors affecting child development depends on the age, quantum and duration of exposure in relation to the period of growth. Important organic factors affecting growth/development include —
a) Prenatal factors affecting child development involving maternal health e.g. maffiutrition, infections and systemic diseases affects growth of offsprings in three different ways — i) during the period of organ differentiation i.e. embryogenesis, leading to higher risk of abortions or congenital malformations; ii) during late fetal phase of anatomical and functional maturation, leading to intrauterine growth retardation (IUGR) or stillbirths, iii) during postnatal life, when matemal ill-health may affect emotional attention & quality of baby-care during critical phase of growth.
b) Obstetrical or perinatal factors affecting child development: Preterms and/or Low birth weight (LBW) babies behave differently than term babies during postnatal growth period — while preterms grow faster in late infancy (catch-up growth) than the term babies, small for gestational age (IUGR) babies are unlikely to show significant catch-up growth and have limited growth potential throughout the life. Other perinatal events e.g. asphyxia/injuries, sepsis, kernicterus etc. may also have disastrous effects on subsequent growth and development.
c) Postnatal factors affecting child development: Postnatal growth is largely governed by hormonal influences e.g. growth hormone in prepubertal period and sex-steroids during puberty; apart from adequate supply of substrates e.g. nutrition, oxygen etc. and freedom from infections.
Malnutrition, chronic infections e.g. tuberculosis and systemic illnesses e.g. asthma,heart diseases etc. are most important adverse factors influencing postnatal growth and development. Head injury may lead to mental retardation while growth of a particular limb may be affected after fractures of long bones. Prolonged steroids/cytotoxic therapy are important causes of iatrogenic growth suppression.
III) Extrinsic (environmental) factors affecting child development are important hindrances for normal growth in developing countries, which indirectly affect nutrition, infection rate and quantum of health care. These include —
a) Socio-economic factors affecting child development: Children of affluent parents have better growth due to better nutrition and hygienic conditions than those of low socioeconomic status.
b) Cultural factors affecting child development: Child-rearing practices vary in different communities, which may significantly impact child’s growth. Routine practice of breast- feeding is a positive growth-promoting factor, while delayed weaning, food taboos and unhygienic living conditions are important adverse cultural influences in India.
c) Emotional factors affecting child development: Adequate emotional stimulation is essential not only for psychosocial and linguistic development of a child but also for growth. Lower growth hormone levels are well documented in emotionally-deprived children like orphans.
d) Climatic factors affecting child development: Growth is slower in summer than in spring season, probably as infections are common and appetite is poor in hot and humid climate. Climate also affects the food productivity.
LAWS OF GROWTH & DEVELOPMENT
Although each child has a unique pace of growth & development, factors affecting child development are applicable to all children, as follows —
a) Growth & development is a continuous and orderly process that begins with fertilization of ovum and continues at every moment of intrauterine and postnatal life till puberty, in a fairly consistent order.
Various stages of growth & development and factors affecting child development may be broadly classified as follows —
Embryonic period (0-8 weeks) is the period of maximum growth, characterized by organ c4(ferentiation i.e. formation of various tissues and organs. Any insult in first trimester is more likely to cause congenital malformations. By the end of this period, a fetus is structurally similar to an adult, except the differences in organ size and function.
Late fetal growth (9th week – birth) is characterized by factors affecting child development like increase in organs’ size (anatomical development) and functional maturation of various systems (physiological development). Any insult in late pregnancy leads to restrictions in body size and organs, termed as Intrauterine Growth Retardation or IUGR. Although a fetus is usually capable to survive ex-utero beyond 28th weeks of life (age of viability), adequate functional maturation is achieved only by 37 weeks (full term).
Postnatal growth during childhood (birth to onset of puberty) involves further physiological maturation and anatomical growth, though the pattern and pace of these changes differ in different body tissues and in different individuals.
Adolescent growth & development from onset to completion of puberty, is the transitional phase between child and adult, characterized by — i) Physical growth spurt to attain adult dimensions, ii) Sexual maturity, and iii) Psychological changes, in order to gain emotional and functional independence.
I) Intrinsic (Biological) factors affecting child development: Age, Sex, Ethnicity – Hereditary trends – Genetic/chromosomal disorders
II) Extrinsic (Organic) factors affecting child development:
- Maternal Nutrition: Malnutrition, anemia
- Intrauterine (TORCH) infections*
- Maternal diseases: Hypertension, Diabetes
- Teratogens: Drugs, Radiation, Smoking
- Placental disorders/insufficiency
- Gest. Age & Birth Weight
- Complications: B.asphyxia, Kernicterus
- Nutrition: Malnutrition, Anemia
- Chronic Infections: TB, Worm infestations
- Systemic illnesses: CHDs, Asthma
- Trauma:Head injury
- Drugs: Steroids, cytotoxic agents
Ill) Extrinsic (Environmental) factors affecting child development
- Socioeconomic factors affecting child development
- Cultural factors/practices
- Emotional stimulation
- Climatic factors affecting child development
b) Pattern of growth is different in different body tissues. All tissues or organs do not grow at the same velocity at same age. Mainly four types of growth patterns are seen in different body tissues:
i) Somatic growth is maximum in intrauterine life and follows a sigma-shaped curve in postnatal life, with two distinct growth-spurts – during infancy and during adolescence. In mid-childhood, child grows slowly but steadily. Somatic growth completes at 16-18 years (earlier in females) with achievement of adult height.
ii) Neurological growth is maximum in late intrauterine and early postnatal life, followed by rapid deceleration in late infancy and is nearly complete by two years of age. Head circumference reaches to 95% of adult value by 2-3 years of age and any further increase is due to the increase in bony thickness rather than brain size.
iii) Gon.adal growth is negligible till the onset of puberty, when gonads grow rapidly under the endocrinal influences to achieve adult size and function during next 3-4 years of adolescence.
iv) Lymphoid growth is maximum in mid-childhood, during 4-8 years of age. Thus, lymph nodes, tonsils and adenoids are physiologically enlarged in this age- group, often confused with a diseased state. Subsequently, these tissues partially regress to adult size after 8-9 years of age.
c) Pace of growth is unique for every child, despite comparable growth potential, determined by familial and racial characteristics. Each child experiences intermittent periods of growth spurts and stagnation. While some children grow rapidly in early life followed by slower pace, others have initially slower growth followed by late catch-up growth. Similarly, the age of achieving a developmental milestone is also markedly variable in different children. Further, some children develop slowly in certain fields of development and faster in other fields. Generally, girls have a faster speech development, while boys develop faster in motor fields.
d) Growth occurs in cephalocaudal direction: During intrauterine life, head and upper torso grows faster than limbs as evident from higher upper vs. lower segment (US:LS) ratio at birth (1.7:1) and the head being larger than the chest. Postnatally, trunk and limbs grow more rapidly with equalization of head: chest circumference by 1 year and US: LS ratio by 7 years. Chest circumference exceeds head circumference beyond first year of life.
In developmental field too, factors affecting child development has cephalocaudal pattern which is evident from the fact that a normal child learns to hold the head first, followed by sifting and than, standing.
Check this video on Science of Early Childhood Development: