Prenatal Development
and the Newborn Period
How Children Develop (3rd ed.)
Siegler, DeLoache & Eisenberg
Slides have been adapted.
Chapter 2
Overview: Major Topics

I. Prenatal
Development

II. The Birth
Experience

III. The
Newborn
Infant
Guiding Questions
1.
What changes occur during prenatal development?
2.
How does the environment contribute to prenatal development?
3.
How does the developing child’s behavior contribute to its own
development?
4.
Can learning occur during the prenatal period?
5.
What is daily life like for the newborn?
6.
What special risks threaten the developing newborn?
Changing Ideas Over Time
Aristotle rejected the
prevailing idea that the
individual was
preformed at the start
of life in favor of
epigenesis, the idea
that there is an
emergence of new
structures and
functions during
development.
What changes occur during prenatal development?
The Reproductive Process


An egg is launched from
one of the woman’s
ovaries into the fallopian
tube.
If sexual intercourse
takes place near the
time the egg is released,
then conception will be
possible.
Conception



Results from the union of two gametes, the egg and the sperm
Gametes are produced through a specialized cell division,
which results in each gamete’s having only half the genetic
material of all other normal cells in the body.
Population sex differences begin at conception. More males
are conceived, but males are more vulnerable after this point.
The Zygote

After conception, the fertilized egg, or zygote, has a
full complement of human genetic material, half from
each parent.
Processes Occurring During
Prenatal Development

These processes transform a zygote into
an embryo and then into a fetus.
1.
2.
3.
4.
Cell division results in the proliferation of cells.
Cell migration is the movement of cells from their
point of origin to somewhere else in the embryo.
Cell differentiation transforms the embryo’s
unspecialized stem cells into different types of
cells.
Apoptosis, genetically programmed cell death,
also enables prenatal development.
Early Development

By the 4th day after conception,
the zygote arranges itself into a
hollow sphere of cells with a
bulge of cells, the inner cell
mass, on one side.

The inner cell mass eventually forms
into the embryo.
The Embryo

After implantation, the inner cell mass
becomes the embryo and the rest of the
cells develop into its support system.

The neural tube is a
U-shaped groove formed
from the top layer of
differentiated cells in the
embryo.

It eventually becomes the
brain and the spinal cord.
How does the environment contribute to prenatal
development?
Teratogens

Environmental agents that
have the potential to cause
harm during prenatal
development.

Timing is a crucial factor
in the severity of the
effects of potentially
harmful agents.
 Many agents cause
damage only if
exposure occurs during
a sensitive period in
development.

Most teratogens show a doseresponse relation.


Increases in exposure to potential
teratogens are associated with greater
probabilities of fetal defects and with
more severe problems.
Individual differences also
influence the effects of teratogens.
Teratogens

Identifying teratogens is made
difficult by the existence of
sleeper effects in which the
impact of a given agent may not
be apparent for many years.

Teratogens include legal as well
as illegal substances...
Legal Drugs: Cigarettes

Cigarette smoking during
pregnancy is linked to
retarded growth and low
birth weight.

Cigarette smoking has also
been linked to SIDS (sudden
infant death syndrome),
although the ultimate causes
of SIDS are still unknown.

Parents can reduce the risk of SIDS by not smoking, putting
babies to sleep on their backs rather than on their stomachs,
using firm mattresses and no pillows as bedding for infants,
and avoiding wrapping infants in lots of blankets or clothing.
Legal Drugs: Alchohol

Maternal alcoholism can lead to fetal alcohol spectrum
disorder (FASD), which is associated with mental
retardation, facial deformity, and other problems.
Illegal Drugs

Approximately 4% of pregnant women in the
U.S. use illicit drugs.

Marijuana is suspected of affecting memory,
learning, and visual skills after birth.

Cocaine-exposed children have reported cognitive
and social deficits.
Environmental Pollutants

Toxic metals, synthetic hormones, and
various ingredients of plastics, pesticides,
and herbicides can be teratogenic.

PCBs (polycholorinated biphenyls) have been
associated with small head size as newborns and
slightly lower IQ scores as long as 11 years later.
Occupational Hazards

Many women have
jobs that bring them
into contact with
potentially
hazardous elements
(e.g., automobile
exhaust, pesticides,
chemicals, noise
pollution).
Maternal Factors

The age, nutrition, disease, and emotional state of
the mother have an impact on prenatal development

Infants born to girls 15 years or younger are three to four times
more likely to die before their first birthday than are those whose
mothers 23-29 years of age.

An inadequate supply of
specific nutrients or vitamins
such as folic acid can have
dramatic consequences.

A variety of diseases including
sexually transmitted diseases
present hazards to the fetus.

A woman’s emotional state can
affect her fetus.
Protecting the Fetus

The placental membrane is a barrier
against some, but not all toxins and
infectious agents.

The amniotic sac, a membrane filled with
fluid in which the fetus floats, provides a
protective buffer for the fetus
How does the developing child’s behavior contribute
to its own development?
The Role of Hormones

Hormones play a crucial role in sexual
differentiation.

All human fetuses can develop either male or
female genitalia, depending on the presence or
absence of testosterone.
Fetal Behavior

By 12 weeks after gestation, most of
the movements that will be present
at birth have appeared.

Prenatal to postnatal continuity

Swallowing amniotic fluid promotes the normal
development of the palate and aids in the
maturation of the digestive system.

Movement of the chest wall and pulling in and
expelling small amounts of amniotic fluid help
the respiratory system become functional.
Behavioral Cycles

Become stable during the
second half of pregnancy

Circadian rhythms are
also apparent

Near the end of
pregnancy, sleep and
wake states are similar to
those after birth
Can learning occur during the prenatal period?
Fetal Sensory Experience

Sensory structures are present
relatively early in prenatal
development and play a vital role in
fetal development and learning.

Visual experience is negligible.

Fetus experiences tactile stimulation as a
result of its own activity, and tastes and
smells the amniotic fluid.

It responds to sounds from at least the
6th month of gestation.
Evidence of Fetal Learning
At 32 weeks
gestation, the
fetus decreases
responses to
repeated or
continued
stimulation, a
simple form of
learning called
habituation.
Evidence of Fetal Learning

Newborn infants have
been shown to
recognize rhymes and
stories presented
before birth.

Newborns also prefer
smells, tastes, and
sound patterns that are
familiar because
of prenatal exposure.
What is daily life like for the newborn?
Newborn States of Arousal

State: The infant’s
level of arousal and
engagement in the
environment

Ranges from deep
sleep to intense activity

Is an important
influence in the
newborn’s exploration
of the world
Six States of Arousal
1.
2.
3.
4.
5.
6.
Active sleep
Quiet sleep
Crying
Active awake
Alert awake
Drowsing
Newborn States
Safe Sleep is Essential

Newborns sleep twice as
much as young adults



The pattern of two
different sleep states
changes dramatically:
REM (rapid eye
movement) sleep: an
active sleep state
associated with dreaming in
adults and is characterized
by quick, jerky eye
movements under closed
lids
Non-REM sleep: a quiet or
deep sleep state
characterized by the
absence of motor activity or
eye movements and by
regular, slow brain waves,
breathing, and
heart rate
REM Sleep

REM sleep constitutes fully 50% of a newborn’s
total sleep time and declines rapidly to only 20%
by 3 or 4 years of age.

According to autostimulation theory, brain
activity during REM sleep in the fetus and
newborn makes up for natural deprivation of
external stimuli and facilitates the early
development of the visual system.
Crying

Early in infancy, crying reflects discomfort or
frustration.

Crying gradually becomes more of a
communicative act.

With experience, parents become better at
interpreting the characteristics of the cry itself.
Crying

Many effective soothing
techniques, including
swaddling, involve
moderately intense and
continuous or repetitive
stimulation.

Parents of babies with
colic should seek social
support and relief from
frustration—and
remember that colic
typically ends within a
few months.
What special risks threaten the developing newborn?
Infant Mortality

Death during the first year after birth
(infant mortality) has become a relatively
rare event in the Western industrialized
world.

However, rates in the United States are the 20th
highest in the world.

African-American infants are more than twice as
likely to die before their first birthday as EuroAmerican babies.

Poverty and lack of health insurance are associated
with high rates of infant mortality.
Low Birth Weight
Infants weighing less than 5.5 pounds
(2,500 grams) are considered to be of
low birth weight (LBW).


LBW infants born at or before 35 weeks after
conception are described as premature.

Other LBW infants are referred to as small for
gestation age (SGA) when their birth weight is
substantially less than the norm for their
gestational age.
Low Birth Weight

As a group, LBW babies experience more
medical complications, have more
developmental difficulties, and present
special challenges for parents.

However, the majority of LBW babies turn out
quite well.

Extensive parent contact and more touch for
infants in neonatal intensive care are widely used
interventions.
Parenting LBW Infants

Parenting LBW babies presents special
challenges due to parents’ feelings of guilt and
inadequacy, the stress of intensive care
treatment, and the infants’ disorganized states.

Parents benefit from understanding that their preterm
infants’ development will not follow the same timetable as
that of a full-term infant, by learning more about infant
development, and by seeking social support and
intervention programs.
Multiple-Risk Models

Risk factors tend to
occur together.

A negative
outcome is more
likely when there
are multiple risk
factors.

Despite multiple
risk factors,
however, some
individuals do well.
Poverty as a Developmental Hazard

The existence of multiple risks is strongly
related to socioeconomic factors.

In many countries, minority families are
overrepresented in the lowest SES levels.
Risk & Resilience

Developmental resilience refers to
successful development in the face of
multiple and seemingly overwhelming
developmental hazards.

Resilient children often experience
responsive care from a particular caregiver
and possess personal characteristics such
as intelligence and responsiveness to
others.