These notes covers briefly Postnatal Development, not in as much detail as prenatal development is covered in this project.
Postnatal development can be broadly divided into the age categories of: Neonatal (birth to 1 month), Infancy (1 month to 2 years), Childhood (2 years to puberty), Puberty (12 years to mid-teens), Young Adult a new category (late teens to early twenties).
As an introduction to postnatal health issues read NHMRC Publications list that relates to child health. Many factors causing abnormal development can also lead to childhood mortality.
In developed countries, we sometimes forget that every year (mainly in developing countries) some 12 million children die before reaching their fifth birthday, many of them during their first year of life. Of these, 70% are killed by one of five causes (diarrhoea, pneumonia, measles, malaria or malnutrition) and often by some combination of them (WHO Fact Sheet N96 November 1995).
For more child population data look at the section below on Child Health Statistics of the world, between and within specific countries.
Page Links: Introduction | Some Recent Findings | Neonatal | Very Low Birth Weight | Infancy | Childhood | Puberty | Young Adult | Nutrition | Childhood Disease | Australian Information | NSW Information | American Information | Normal Health Statistics | Postnatal Neural Development | Reading | References | Glossary
Child health and survival in the Eastern Mediterranean region "Fifteen per cent of deaths in children under 5 around the globe occur in the Eastern Mediterranean Region and half could be prevented by cost effective evidence based interventions." "..Over 10 million children aged under 5 years die every year, almost 90% of them in a few countries in sub-Saharan Africa and South Asia.1-6 Landmark series on child and neonatal survival suggested that this high mortality persists despite low cost solutions being known and that almost 60-70% of these deaths could be prevented by making these interventions widely available." BMJ - Editorial Zulfiqar A Bhutta, Asim Belgaumi, Mohammad Abdur Rab, Zein Karrar, Mohamed Khashaba, and Nezha Mouane Child health and survival in the Eastern Mediterranean region BMJ 2006 333: 839-842.
Cortex Matures Faster in Youth with Highest IQ (More? Postnatal Neural Development)
Card JP, Levitt P, Gluhovsky M, Rinaman L. Early experience modifies the postnatal assembly of autonomic emotional motor circuits in rats. J Neurosci. 2005 Oct 5;25(40):9102-11. "...These findings support the view that environmental events during early postnatal life can influence the formation of neural circuits that provide limbic and cortical control over autonomic emotional motor output."
(birth to 1 month)
A period of extensive and ongoing system transition from uterine environment to external world.
VLBW neonates are between 401 to 1500 grams. The table below shows USA (NICHD) data for VLBW infants who survived beyond 3 days and had one or more episodes of blood culture-proven sepsis, the common cause of infection by gram-positive organisms, and the percentage of these resulting from coagulase-negative staphylococci.
Years |
Blood culture-proven sepsis |
Gram-positive organisms |
Staphylococci |
1991-1993 |
25% |
73% |
55% |
1998-2000 |
21% |
70% |
48% |
Reference:Stoll BJ, Gordon T, Korones SB, Shankaran S, Tyson JE, Bauer CR, Fanaroff AA, Lemons JA, Donovan EF, Oh W, Stevenson DK, Ehrenkranz RA, Papile LA, Verter J, Wright LL. Late-onset sepsis in very low birth weight neonates: a report from the National Institute of Child Health and Human Development Neonatal Research Network. J Pediatr. 1996 Jul;129(1):63-71.
Stoll BJ, Hansen N, Fanaroff AA, Wright LL, Carlo WA, Ehrenkranz RA, Lemons JA, Donovan EF, Stark AR, Tyson JE, Oh W, Bauer CR, Korones SB, Shankaran S, Laptook AR, Stevenson DK, Papile LA, Poole WK. Late-onset sepsis in very low birth weight neonates: the experience of the NICHD Neonatal Research Network. Pediatrics. 2002 Aug;110(2 Pt 1):285-91.
(2 years to puberty)
During this time several systems continue to develop. For example, neurological (ongoing growth and cellular reorganisation) and respiratory (continues to grow until approx. 8 years of age) systems. (More? Postnatal Neural Development)
Early growth and development in humans and other mammals, by definition, is based largely upon nutrition from milk. (More? milk)
More recently the issue of poor nutrition has been linked to the developed world literal growing problem of childhood obesity.
See also the European Union investigation into the long-term consequences of early nutrition by metabolic programming in the Early Nutrition Programming Project
There are many different diseases that can impact on postnatal development, the most serious of which result in death. Some postnatal diseases may also have different outcomes dependent upon availability of medical support, though even in developed countries other factors can also impact on outcomes.
For example, a recent British Medical Journal (BMJ 25 June 2005) article "Outcome of meningococcal disease in children" identified in this UK study (of 498 children) three independent factors associated with an increased risk of death: not being cared for by a paediatrician, junior staff working with not enough supervision, and failure of staff to administer adequate inotropes.
Meningococcal disease, also called "meningitis", is a viral or bacterial infection of cerebrospinal fluid of the spinal cord and brain. Treatment and outcomes differ for either viral (less severe, resolves without specific treatment) or bacterial (severe, may result in brain damage, hearing loss, or learning disability) infections. For bacterial meningitis, determining the type of bacteria is important because antibiotics can prevent some types from spreading and infecting other people. Before the 1990s, Haemophilus influenzae type b (Hib) was the leading cause of bacterial meningitis, but new vaccines being given to all children as part of their routine immunizations have reduced the occurrence of invasive disease due to H. influenzae. Today, Streptococcus pneumoniae and Neisseria meningitidis are the leading causes of bacterial meningitis. (text modifed from CDC information - More? CDC - meningococcal disease | technical information)
NHMRC- Publications Relating to Child Health Publications List
NHMRC Infectious Diseases School Exclusion recommendations
Institute for Child Health Research (WA), internet required
http://www.ichr.uwa.edu.au/about/intro.html
The following are links to PDF documents prepared by NSW Health designed for clinical care (not patient information). Clinical Practice Guidelines for Paediatric Care
Acute Management of Infants and Children with: Bacterial Meningitis | Otitis Media | Fever | Asthma | Croup |
American Medical Association- "Kids Health" (these are easy to read general public pages American not Australian Information )
International and Australian Population Statistics
WHO Normal Population Statistics
Global Perinatal and Maternal Causes of Death
Population Comparisons between Countries
USA National Center for Health Statistics - Child
Normal population statistics derived from a number of different sources (as shown on individual pages).
Neurological development contiues postnatally with both growth and reorganization of the central nervous system.
Recent NIH research has looked at the postnatal development of the cortex in children (Cortex Matures Faster in Youth with Highest IQ) "The researchers found that the relationship between cortex thickness and IQ varied with age, particularly in the prefrontal cortex, seat of abstract reasoning, planning, and other "executive" functions. .... While the cortex was thinning in all groups by the teen years, the superior group showed the highest rates of change."
(More? Postnatal Neural Development)
In addition, there are several developmental neurological abnormalities that are diagnosed postnatally as learning disorders. (More? Autism | Fragile X | Neural Notes - Autism | Neural Notes - Fragile X)
(More? Postnatal Neural Development)
Most embryology textbooks (by definition) do not cover postnatal developmenty in any detail. The links below are to useful external online resources.
Links: Reviews | Articles | Online Textbooks | Search Textbooks | Search PubMed | Glossary
Articles
Search PubMed
Search Feb 2006 "postnatal human development" ?? reference articles of which ?? were reviews.
Search PubMed: term = postnatal human development
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It would seem obvious to say that development does not stop at birth. In fact many systems (cardiovascular, respiratory, gastrointestinal, homeostasis) undergo significant changes at birth, and many others (neural) have not yet completed their development.
Note this current project focuses on prenatal development, so postnatal content is not as detailed.
This section of notes covers issues related to early childhood and development. It is sometimes easy to forget the many health issues that affect childhood development around the world. There are many links to external resources that relate to the many issues of this period of development.
Following childhood we have the early teenager, where hormonal changes trigger changes that lead to growth and reproductive maturation.
Please email Dr Mark Hill if you wish to make a comment about this current project.