1. Prenatal, Infancy, & Early Childhood
Human Development
Prenatal, Infancy, & Early Childhood

2. Prenatal Period Stage 1: Germinal (conception- 2wk)
Ovum + Sperm = fertilized egg called a zygote (46 chromosomes, 23 from each parent)
Zygote starts as a single cell & begins to divide
2wk it attaches to the wall of the uterus & placenta forms (this is the beginning of the next stage)
Many zygotes rejected at this point (1 in 5 pregnancies end with woman not aware she was pregnant)

3. Genetic Abnormalities
Turner syndrome: XO
Sperm contributes nothing and baby develops female but can’t reproduce because don’t have reproductive organs
Usually short

5. Genetic Abnormalities
XXY
Klinefelter’s syndrome
Live as men, looks and raised male but small penis and testes.
Low androgen secretion and possible female breast development
A feminizing male

6. Genetic Abnormalities

7. Genetic Abnormalities
XXX
Sperm contributes too much
Looks female
Tend to be normal female.
Don’t even know they have it.

8. Stage 2: Embryonic (2-8 wk)
Zygote is now called an embryo- begin to differentiate between bone, muscle & organs
Very fragile since basic organs are begin formed (heart, spine, brain, genitalia)
Teratogens- toxic agents that cross the placenta
Major birth defects can occur & most miscarriages occur in this stage

9. Prenatal Hormone Abnormalities
Andrenogenital Syndrome (AGS)
Too much androgen is released to the fetus. Not a problem if you’re a male but females are masculine.
Genitalia will masculinize and more like a tomboy.
Androgen Insensitivity syndrome (AIS)
Baby doesn’t detect androgen. Boys don’t masculinize they develop female (XY)
No internal sex organs
They are XY females.
At puberty they grow breasts but do not menstruate.

10. Stage 3: Fetal (2 mo- birth)
Embryo now called a fetus
Vital organs develop & physical characteristics distinctly human
Capable of physical movement
Respiratory & digestive system matures
22-23 wk fetus may reach age of viability- can survive in the event of premature birth
26-28 wk survival rate 85%

15. Birth
Premature- the more premature and underweight the baby is the greater chance of physical & mental impairment
Power of Touch- premature babies gently massaged 3x a day show significant weight gain, more rapidly maturing nervous system, & higher activity
Anoxia- loss of oxygen to nerve cells can lead to motor paralysis (cerebral palsy)

16. Some Influences on Prenatal Dev.
Severe Maternal Malnutrition
Increase risk of birth complications & neurological defects
Often confounded with poverty, drug use, & limited access to health care
All Recreational Drugs (E.I- cocaine, narcotics)
Born addicted
Increase risk of early death due to prematurity
Birth defects- particularly respiratory problems

17. Some Influences on Prenatal Dev.
Alcohol- Fetal Alcohol Syndrome
Correlation btw amount of alcohol consumed & damage to offspring
Microcephaly (small head), heart defects, hyperactivity, delayed mental & motor skills, leading cause of mental retardation
Increase incidence of depression, suicide, & criminal behavior in adulthood
Smoking
Increase risk of miscarriage, prematurity & sudden infant death syndrome (SIDS)
Slower cognitive development, ADD

18. Cross-Cultural Comparison of Infant Mortality
Infant mortality is the death rate per 1,000 births during 1st year of life
US ranks only 21st in the prevention of infant mortality
Why?

19. Infant Mortality Rates

20. Reflexes at Birth
Rooting- turn head toward anything that touches cheek
Sucking- suck on anything that enters mouth
Swallowing- swallow liquids w/o choking
Grasping- wrap their fist around anything that enters their hand
Stepping- make stepping motion if held just above the ground

21. Sensory Dev Vision Hearing Smell & Taste
1-3 mo distinguish mom’s face with that of a stranger
Imitates facial expressions of an adult
3-4 years have visual abilities equal to an adult
Hearing
1 mo keen hearing & can discriminate between small sound variations such as bah & pah
6 mo have developed ability to make all sounds necessary to learn language
10-13 mo first words
Smell & Taste
1 day old can tell difference between citrus & floral odor
6 wk can smell difference between their mom & a stranger
Innate taste preference for sweet things

22. Maturation- developmental changes that are biologically programmed rather than learned
Walking- all humans learn it but sometimes when we learn it depends on culture
Head size decreases in proportion to body size as one gets older
In first 3 mo babies’ body weight & brain size doubles
Developmental Norms- average age at which children perform various tasks

24. Gross Motor Skills (larger muscles of the body)
5.5 mo- sitting up alone
10 mo- crawling
1 yr- walk alone
1.5 yr- up and down stairs

25. Fine Motor Skills (smaller muscles of the body)
2 yr- clumsy at picking up objects, can hold cup with one hand, start to use spoon
3 yr- use scissor & button clothes
4 yr- change clothes by themselves, eat with utensils
5 yr- begin to write

26. Drawing- type of fine motor skill
Serves purpose of sensory exploration & to express emotion
Pre-representational- scribbles, focus is on activity itself
Representational- drawing means something to the child, 4 yr old can draw stick figures