Postnatal development follows prenatal growth patterns, with rapid growth after birth, followed by steady growth and another growth spurt during adolescence. Growth curves for height and weight form an S-shape pattern. Gender affects the timing and extent of growth, with girls maturing faster than boys on average. Physiological maturation can advance without increasing size. Secondary sex characteristics emerge during puberty. Genetics, environment, nutrition, and health all influence postnatal development. Growth monitoring tracks development against standardized charts.

1. Postnatal development

2. Overall Growth
 Body growth after birth is a continuation of prenatal growth
 The growth curves for height and weight are characterized
by rapid growth after birth, followed by gradual but steady
growth, rapid growth during early adolescence, and then a
leveling off.
 Thus, the curves are s-shaped (a sigmoid curve)
 The sigmoid pattern of a graph of overall growth is
universal, but the timing and steepness of segments of the
curve are specific to the individual

5. Factors affecting development
1- Gender
 Gender is a major factor in the timing as well as the extent
of growth. Gender differences are minimal in early
childhood, with boys being very slightly taller and heavier
 Girls tend to mature at a faster rate than boys.
 Girls begin their adolescent growth spurt when they are
about 9 years old, boys begin theirs at about 11 (these ages
are group averages). About two thirds of all adolescents
will initiate their growth spurts during the year before or
the year after these averages.

6. Height
 A rapid increase in infancy, tapering off to steady
growth in childhood, with another rapid increase
during adolescence, followed by a tapering off until
the end of the growth period
 The individual curves represent various percentiles,
this allows to approximate at what percentile an
individual falls for height at a specific age, as well as
he/she maintains position in the group or changes.
 Children tend to maintain their relative percentile
position in comparison to group norms after they
are 2 or 3 years old
 A large fluctuation in relative position could indicate
indicate some extrinsic factor is influencing growth

8. •To examine the rate, or velocity of growth:
When the rate of growth is
plotted, find the age at which
one is growing the fastest
(peak velocity) or the age at
which one changes from slow
growth to rapid growth (age
of takeoff)

9. -On the average, girls reach their peak
height
velocity at 1 1.5 to 12.0 years
-Their growth in height then tapers off at
approximately age 14, with notable
increases in height ending around age 16.
Boys reach their peak height velocity at 13.5
to 14.0 years
-Velocity approximately 9 cm/yr for boys
compared to 8 cm/yr for girls.
- Boys' growth tapers off at 17 years, with
notable increases ending by age 18.

10. Height is stable through adulthood.
It is common for an individual's stature to
decrease slightly in older adulthood: due to
-The compression and flattening of the body's
connective tissues (cartilage between the
vertebrae) resulting in a decrease in trunk length.
-The bones lose density due to progressive
modifications in the protein matrix of the
skeleton.

12. Weight
 Growth in weight also follows the sigmoid pattern of growth:
 a rapid increase in infancy,
 Moderate increase in childhood
 A spurt in early adolescence,
 Then a steady increase that tapers off at the end of the growth period.

13. Weight
Weight is susceptible to extrinsic
factors and can reflect variations
in the amount of muscle with
exercise as well as variations in
the amount of fat tissue with diet
and exercise.
Disease can also influence body
weight

14.  Peak weight velocity follows peak height velocity in adolescents by 2.5
to 5.0 months in boys and 3.5 to 10.5 months in girls.
 The growth of various segment lengths and breadths reach peak velocity
before the individual reaches peak height velocity and sometimes after,
but all reach their peak before or at peak weight velocity

15.  Adults typically start gaining weight at early 20s due to changes in
lifestyle.
 Adults who exercise regularly and eat wisely often maintain their
weight or even gain muscle and lose fat.

16. Relative Growth
Specific body parts, tissues, and organs
have differential rates of growth.
Each part of the growing individual has
its own precise and orderly growth rate.
Body proportions at birth reflect the
cephalocaudal (head to tail) and
proximodistal (near to far) directions of
prenatal growth.

18.  The head is1/4 of the total height at birth But only 1/8 of adult
height
 The legs are about 3/8 of the height at birth but almost ½ of adult
height
 from birth to maturity, the length of:
1. the head increases about 2 times.
2. the trunk increases about 3 times.
3. the arms increase about 4 times.
4. the legs increase about 5 times

19.  In childhood, the legs grow faster than the trunk and the head with
a growth spurt in adolescence.
 Growth in height results from an increase in trunk length during late
adolescence.
 Boys and girls have similar proportions in childhood, but by the
time there are differences between the sexes.
 Specific tissues and organs grow differentially. The brain, for
example, achieves more than 80% of its adult weight by age 4.

20. Physiological maturation
 Tissues of the growing body can advance
without necessarily increasing in size.
 Organs and systems can advance
qualitatively. This is termed, Physiological
maturation.
 It is difficult to infer maturity from age alone,
from size alone, or even from age and size
considered together.

21. Secondary Sex
Characteristics
 Girls have a rapid rate of maturity than boys. They enter their adolescent growth
spurt sooner, and their secondary sex characteristics appear sooner.
In male:
 the voice changes, becomes deeper.
 development of muscle tissue and a growth spurt.
 growth of body hair - pubic, chest, and face.
In female
 change in body shape, rounder hips.
 development of mammary glands.
 growth of pubic hair.
 increase in fat tissue; essential for fertility.
 Menarche.

22. Secondary Sex Characteristics
 Menarche typically follows the peak height velocity by 11 to 12
months.
 The average age of menarche therefore is 12.5 to 13.0 years.
 Individuals who are more mature are likely to be stronger and more
coordinated than those who are less mature, even at the same
chronological age

23. Factors Affecting Development
Genetics
Maturation
Environment

24. Genetics
Control the
timing and rate
of growth.
Determine such
characteristics
such as sex,
physical, status
and race.

25. Maturation

26. Environment
 Affects an individual growth
and development, some of
these are: family, religion,
climate, culture, school,
community and nutrition.
 In the early years this is
primarily the family.

27. Catch-up Growth
 A child might experience catch-up growth after
suffering a period of severe malnutrition or a severe
disorder such as chronic renal failure.
 During such a period, body growth is retarded.
 After the diet is improved or the child recovers, growth
rate increases until the child approaches or catches up.
 Whether the child recovers some or all of the growth
depends on the timing, duration, and severity of the
negative environmental condition.

28. Catch-up Growth

29. Growth Monitoring
 Growth should be measured and compared with statistical
norms in a standard fashion.
 This is achieved by Growth Charts.
 Comparing body measurements with the appropriate age-
and sex-specific growth chart enables health care providers to
monitor growth and identify potential health- or nutrition-
related problems
 WHO charts – blue for boys and pink for girls

30. Growth Monitoring: Steps
1. Obtain accurate measurements.
2. Select the appropriate growth chart:

31. Growth Monitoring: Steps
3. Record data.
4. Calculate BMI when a child is
aged 2 to 20 years.
5. Plot measurements.
6. Interpret the plotted
measurements.

33. Uses of Growth Chart
 Diagnostic tool-To identify high risk children.
 Education tool for educating mothers.
 Tool for action helps in type of intervention
that is needed.
 Evaluation of effectiveness of corrective
measure and impact of a program of special
interventions for improving child's growth
and development .
 Calculate drug dosage