(1) The document summarizes key stages of prenatal development from conception through the germinal, embryonic, and fetal periods, ending with birth. It describes the formation of the zygote, morula, blastocyst, and how the three germ layers form. (2) During the embryonic period, the amnion, amniotic fluid, chorion, and placenta provide nutrition and protection for the growing embryo. Organs begin to form and differentiate. Sexual differentiation occurs from weeks 7-9. (3) In the fetal period, rapid growth and development of organs occurs. The fetus can sense motion, sound, and light. Maternal stress, nutrition,

1. Lecture 3
Prenatal Development
& Birth
Ching-fen Hsu
2013/10/4

2. Growth After Conception
• From a zygote
• Dramatic change in size
• Consist 2 billion cells & weigh 7
pounds
• Study of prenatal development
seeks to explain how changes
in form, size, & behaviour take
place
• Different stages emerge
• New stage == the developing
organism + changing E
• Mother’s nutrition has effect
• Birth: endpoint of conception
• Trace E factors to support or
threaten development

3. Prenatal Development Periods
Nucleus
Cell matter
Zona pellucida
(1) The germinal period
from conception to attachment
to the wall of uterus
about 8-10 days
(2) The embryonic period
from attachment to 8th week
all major organs form primitive
shapes
(3) The fetal period
bone hardening
from 9th week until birth
25% pregnancies end before
awareness

4. The Germinal Period

5. The First Cells of Life
• Cleavage: 24 hours after
conception during zygote
travelling down the fallopian
tube
• Hundreds of cells produced
by reaching the uterus
• Heterochrony (variability in
time): different parts of
organism develop at different
rates
• Heterogeneity: variability in
levels of development of
parts
e.g., hearing > seeing

6. Emergence of New Forms
• After 4 or 5 days conception morula cells become smaller
as body cell
• Morula enters uterus (fluid passes into morula)
• Central cells (inner cell mass, later embryo) + outer layer
(trophoblast, [1]protective barrier, [2]later membranes for
transmitting nutrients, [3]pump life-giving fluid from uterus)
[4]remove
waste
products for
dividing cells
& growing of
organism

7. Epigenesis
What makes the different groups of cells take on different
forms?
Epigenesis
• At the time of generation (Greek)
• New form = interaction of preceding form + E
• Es in blastocyst: (1)inside cells surrounded by other cells
(2)one side cell contacts with zona pellucida (3)mother’s
fluid exchanges with E in blastocyst
• Interactions between cells (with each other) and E
conditions create (1)new kinds of cells (2)new form of
interaction between organism & E
• Implantation: the process by which blastocyst becomes
attached to the uterus (branch to uterus’s blood vessels)

8. •
•
•
•
•
•
Stem Cells
Specialized kinds of cells
Have unique ability to renew cells
Give rise to wide variety of other cells
1 week after conception
Inner cell mass of blastocyst
Totipotent (totally potent): any stem cell has potential to develop
into a fully formed baby
• Pluripotent (multiply potent): after stem cells differentiate into 3
germ layers (胚葉)－mesoderm, endoderm, ectoderm
• Replacement cell or tissue sources for Parkinson’s,
Alzheimer’s, spinal cord injury, stroke, burns, heart disease,
diabetes, rheumatoid arthritis
• Stem cell research for human health in ethical ways (currently
deliberate abortion in blastocyst [totipotent] & fetuses
[pluritopotent])

9. The Embryonic Period

10. Sources of Nutrition &
Protection 6 weeks in
• After implantation,
embryonic period
Human embryo 3 weeks
Human embryo 5 weeks

11. Functions of Protective
Environment
• Amnion: thin tough transparent membrane holds amniotic
fluid surrounding the embryo
• Amniotic fluid: provides liquid support for weak muscles &
soft bones & medium for moving & changing positions
• Chorion: another membrane & part of placenta
• Placenta: complex organ made up from mother & the
embryo; barrier from direct contact of bloodstreams of
mother & embryo; filter to exchange nutrients & oxygen;
converts nutrients from mother’s blood for embryos;
enables embryos’ waste products being absorbed
eventually by mother’s kidney
• Umbilical cord: links embryo & placenta

12. Embryonic Growth
• Inner cell mass begins to differentiate into various kinds of
cells which turn into organs
• First step: two layers separation
(1)ectoderm---outer layer: outer surface of skin, nails, part
of the teeth, lens of eyes, inner ear, nervous system(brain,
spinal cord, nerves)
(2)endoderm---inner layer: digestive system, lungs
• Second step: one layer formation
(3)mesoderm---middle layer: muscles, bones, circulatory
system, inner layers of skin
• Organism develops in two patterns: cephalocaudal pattern
(from head down), proximodistal pattern (from center to
periphery) [spinal cord < arm; upper arm < forearm]

14. Sexual Differentiation
• First 6 weeks after conception no genetically gender
difference in structure
• Gonadal ridges appear in fetuses
• From 7th week male gonadal ridges begin to form
testes
• Several weeks later, female ovaries begin to form
• Male gonads (androgens) == gender key
• Testosterone suppresses pituitary gland (for
hormone secretion to form female menstrual cycle)

15. The Fetal Period

16. Fetal Growth
• From 8th/9th week until birth
• Length increases from 1.5 inches
(3.8cm) to 20 inches (50.8cm)
• Weight increases from 0.02 pounds
(0.009kg) to 7.1 pounds (10.32kg)
• Organ complexity
• 10th week intestines in position
• 12th week clear gender
• 16th week erect head, lower limbs well
developed & ear migration from neck to
sides of head
• Mother’s digestive system &
• 5th month fetus’ nerve cells as a person
heart == sources of noise
• Movements == motion stimuli • 7th month lungs breath & eyes respond
to lights
• Placenta & umbilical cord ==
pathways affect the child
• 8th month folds of the brain are present
• 9th month wrinkled brain
• Before birth fetus doubles in weight

17. Sensory Capacities
• How the fetus is influenced by uterine E?
(1) Sensing motion: vestibular system (balance) in
middle ear functions in 5th month & fully mature at
birth
sense mother’s postural changes
sense itself floating inside fluid-filled E
(2) Seeing: 26th week fetus respond to lights (heart rate
changes, body movement)
(3) Hearing: 5th or 6th month 75 db (air passes through
mother’s stomach, mother’s heartbeat, mother’s
voice)
newborns prefer sounds heard in uterus > mother’s
natural voice

18. Fetal Activity
• From 8th week embryo becomes
active for development
• Body movements in fetal period
are varied & coordinated
• 15th week fetus acts as newborn
head-turning, leg flexing (4th
month mom can feel it)
• 24th week (6th month) to 32th
week (8th month) fetal inactivity
(high rate of quiet periods) for
neural pathway development
• Movement inhibition is related
to brain maturation of higher
functions

19. Brain Maturation
• Spontaneous fetal
activity == crucial in
development
chick embryo’s
prenatal activity
correlated with normal
limb development
• Fetal movements ==
establish basic
neuronal connections
in humans
• Breathing movements
with chest & lungs =
respiration muscles

20. Learning in the Womb
• The cat in the hat story
• Twice a day for 1.5 month
before due
• 16 pregnant mothers
• 3.5 hours totally
• Tested newborns after 2 or 3
days
• Half increased sucking rate/half
decreased
• Newborns’ learning in the
womb influenced sounds they
found rewarding after birth

21. Maternal Conditions &
Prenatal Development

22. Maternal Attitudes &
Stress attitudes &
• Pregnant women’s
feelings of the fetus influence
children after birth
• Unwanted children weighted less
& needed more medical help
• Under stress or emotionally upset
released more hormones
(adrenaline & cortisol) via
placenta to have effect on child’s
motor activity (more aggressive)
• Stress relates premature delivery

23. Nutritional Influences
• Folic acid (one member of vitamin B complex) in green
vegetables & fruit
• Calcium in milk
• Iron to prevent birth defects
• 1941 Leningrad (St. Petersburg) encircled by German
army & resulted in famine until 1942 February
• Four slices for factory workers & two slices for
everyone else
• Infants born were lower than normal & weighted less
(< 2500 grams) & premature & poor condition at birth
• Nutrition deprivation in early 3 months: CNS defects,
premature, death; later 3 months: retard fetal growth

24. United Nations Children’s Fund (1999), poor economic conditions create a set
of risk factors, including poor health conditions, parents’ lack of education

25. Birth: The First BioSocial-Behavioural Shift

26. The Baby’s Experience of Birth
•
•
•
•
Stressful for babies
Through narrow opening canal with lots of pressure on head
Umbilical cord may be constricted reducing oxygen supply
Newborn’s biological mechanisms in birth--surge of adrenaline and other ‘stress’ hormones in the fetus
(1) prepare newborns to survive outside the womb
(Lagercrantz & Slotkin, 1986)
cesarean-section-newborns usually have breathing
difficulties
facilitate liquid absorption from lungs
production of surfactin allow lungs’ functioning well
(2) make an increase in newborns’ metabolic rate = nourish
cells
(3) Increase blood flow to vital organs (heart, brain, lung)
(4) put newborns in alert states for about 40 min

27. Childbirth in the US
• Centers for Disease Control and Prevention
(2000)
• Strong preference giving birth in hospitals (99%)
(1) Trained staff providing antiseptic
surroundings & help to any complications
(2) Professional usage of drugs reducing pain in
childbirth
• 1915---100/1000 infant death in 1st year, 8/1000
mother death
• 1997---7.2/1000; 7.7/100,000
• Two main issues concerned--(1) What is the safest method for dealing with
pain during childbirth?
(2) What precautions are necessary to ensure
the health of the mother and the baby?
• Jones (1997)--anesthetics/analgesics/sedatives
• Less attentive, more irritable, poorer muscle
tone, less vigorous sucking responses, weaker

28. First Construction of Social
Relationship
Before birth
• Amniotic fluid--providing warm/wet
environment
• Fetus---receiving
oxygen & nourishment
through the umbilical
cord
After birth
• Lung---taking in oxygen
& exhale carbon dioxide
• First breath---shutting off
bypass that shunts blood
away from lungs to the
placenta; close down the
umbilical arteries; cut off
fetal circulation to the
placenta
• Sucking---nourishment
= Birth is the first bio-social-behavioral shift in human
development

29. Cultural Variations in
Childbirth
• Bajura, eastern Nepal---women deliver in
animal sheds, cut & tie umbilical
cord/wash clothes, care for newborns
themselves (CARE, 2003) == rural
France 19th (Gelis, 1991)
• Ngoni, east Africa---make secret to
husband, men excluded
completely/banished/stuff-removed/return
after childbirth (Read, 1968)
• Maya, Yucatan peninsula---husband
stays, witness the process (Jordan, 1993)
• 1/3 home births in Holland (Jordan, 1993)

30. The Newborn’s Condition
• Disappointment of the first image of real neonate’s
appearance
• Large proportion of baby’s head
• Small limbs
• Misshapen head after tight squeeze
• Skin covered with vernix caseosa (white, chessy
substance to protect against bacterial infections), spotted
with blood
• 5.5-10 pounds normal birth weight
• 7-7.5 pounds average in the US
• 7% weight loss in the first days for fluid loss
• Gain weight 10 after days old
• 20 inches normal length

31. Assessing the Baby’s Viability
• Physical condition check---Apgar Scale (1953)
• Total score less in 4 = immediate medical attention
needed
• Behavioural condition check---Brazelton Neonatal Assessment Scale (1984)
• Assess developmental process of infants & evaluate intervention
effectiveness
1. Orientation to animate objects-visual & auditory (does the baby focus on
the examiner?)
2. Pull-to-sit (how well is the baby able to do so?)
3. Cuddliness (how does the baby respond? Passively or cuddle up to the
examiner?)
4. Defensive movements (how does the baby react to the cloth on face?)
5. Self-quieting activity (how does the baby quiet herself?)

32. Parent-Child Relationship
• Two factors come into play right after birth--(1) initial reactions to baby’s appearance from
parents
(2) parents’ expectations for babies

33. Baby’s Appearance
William Fullard & Ann Reiling (1976)---picture Konrad Lorenz (1943) Babyness
preference study
1. Adult women: infant pictures
2. 7-12y kids: adult pictures
3. 12-14y teens girls: infant pictures
Physiological
4. 14-16y teens boys: infant pictures changes for
reproducing
Weiss (1977)---malformed offspring
1. Killed by mothers
2. less frequent interaction
3. less loved
4. Less competence attributed from mothers
Langlois (1995)--Less-attractive-babygirl-mothers > attractive
babygirl-mothers paid attention on others

34. Social Expectations
• Adjustment of expected-gender
• Sweeney & Bradbard, 1988--• Female fetuses: softer, littler, cuddlier, calmer, weaker,
more delicate, more beautiful than male fetuses
• Rubin et al., 1974--• Girls: little, beautiful, pretty, cute, resembling as mothers
• Boys: big, resembling as fathers
no difference on Apgar Scale of girls and boys
Fathers > mothers have stereo-type concept to genders

35. Does Gender Matter?
•
•
•
•
What babies are named
How they are dressed
How they are treated
What will be expected in later life
• MacFarlane, 1977--• Expectations shape how parents treat babies right
from the start
• Babies are biological organisms and cultural entities
• Babies are shaped by community ideas & have
different experiences to adulthood
• Men & women have different roles to play

36. Cultural Organization
Zincantecos, south-central Mexico
Sons: digging stick, ax, strip of palm for weaving mats
Daughters: weaving stick
Thus--Genetic force (nature) and environment/culture
experience (nurture) shape developments of children
The relationship between child and parents that
begin at birth is an essential foundation on which
later development builds

37. Mother-Newborn
Bonding
Mother-infant bonding at birth = important to later
development
Klopfer et al., 1964--#1 baby goat removed right after birth
return later
= mother goat attacks it!
#2 baby goats stay with mom 5 min
being removed several hours
return later
= mother goat welcome it back!

38. Maternal Bonding
Klaus, Kennell, et al., 1970--Mothers with premature babies were less contacted with /interested in
babies after separation in incubators!
1974--Control group: a glimpse after birth, brief contact with newborns between
6-12hr later, 20-30min visit for bottle-feedings every 4hr; baby stays in
nursery
Experimental group: hold newborns 1hr in 3hr after delivery, skin touch
with newborns having diapers, 5hr together every afternoon 3 days
= 1-month-later, mothers in EG show more interested in infants, gaze
them more, fondle them more than mothers in CG
= 11-month-later, EG mothers are more attentive to infants, more
responsive to their cries than CG mothers
Mother-newborn bonding after birth in close physical contact
immediately, they bond together via complex interactions

39. Premature Caring
• Reconsidering Klaus & Kennell’s study
1. Small population (N=14/group), nonrepresentative
sampling (poor African Americans)
2. EG mothers might be aware of special treatments
influencing their behaviours
3. Replication failures (Eyer, 1992; Rutter, 1995)
•
•
•
•
Kirsten et al., 2001--Early bonding of parent-infant helps high-risk newborns
with premature delivery
Furman & Kennell, 2000--Skin-to-skin contact results in increased nutritional
benefits & greater parental caring & attention

40. Prematurity
• < 37w gestation age =
preterm/premature
• Immaturity of lungs (1st)
• Digestive/immune system (2nd/3rd):
sucking, breathing, swallowing
• Preterm-related disorders (4th)
• Twins might be born 3w earlier
• Young women with immature
reproduction system, smoked-moms,
poor-health-moms, infected-uterusmoms, having had many pregnancies
close together
• Poor women are twice higher in rate
• Cultural factors (fertility drug & fasting)
• Many other unknown reasons

41. Kangaroo Caring
Heart rate & respiration change in incubators &
with mothers
T1
T2
T3

42. Low Birth Weight
Fetal growth retardation: 10% behind normal grown rate
Meara (2001)-->> multiple birth, intrauterine infections, chromosomal
abnormalities, maternal smoking, use of narcotics, maternal
malnutrition, abnormalities of placenta/umbilical cord
Prematurity & low birth weight co-occur always
2/3 newborn death
Holcroft, Blakemore, Allen, & Grahem (2001)--= Neurologically-based developmental handicaps
The smaller the baby, the greater the risk
Holsti, Grunau & Whitfield (2002)--= coordination problem, intellectual capacities decrease
7-11yr vs. normal birth weight = overall poorly on motorcoordinating-tests, intelligence, arithmetic

43. Developmental Consequences
Lorenz (2001)--Normal-size-preterm-babies in gestational age stand a good chance of
catching up with full-term babies
Foreman et al. (1997)--Still, babies with (1) attention-maintaining problems
(2) visual-motor coordination problems in school age
Developmental difficulties
>> premature babies, low birth weight babies, complex medication
history babies
Liaw, Meisels & Brooks-Gunn (1995)--Comfortable socioeconomic circumstances & better education mother
have benefits in raising children without these factors
Strathearn, Gray, O’Callaghan & Wood (2001)--More serious developmental problems in later years if premature babies
raised in impoverished environments or having neglectful parents

44. Environmental Sources
of Birth Defeats

45. Teaching
Implications
許靜芬。2012。
環境是健康人格的
基礎。蒙特梭利雙
月刊，103期，第
10-12頁。

47. Questions?