Prenatal Development and the Newborn period

Question 1

The Code of Life

Answer 1

Genes: deoxyribonucleic acid
molecule (DNA)
Chromosomes: Rod-shaped DNA
portions in 23 pairs
Contain genetic
blueprint for individuals
Replicate through
mitosis

Question 2

Conception

Answer 2

Union of two gametes(sex
cells): egg and sperm
Each gamete contains half of the
genetic material found in other
cells (23 chromosomes)
*Zygote = fertilized egg (46
chromosomes)
*Timing of gamete creation
different for males and females!

Question 3

The Blastocyst

Answer 3

By 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
Inner cell mass eventually becomes
embryo

Question 4

Developmental Processes Cell Division
From Zygote to Blastocyst to Embryo to Fetus

Answer 4

Cell Division Begins ~12 hours after
fertilization
Cell Migration
Cell differentiation
Apoptosis (cell death)

Question 5

Stage 1: Germinal Stage
(fertilization to 2 weeks)

Answer 5

Fertilized egg becomes
blastocyst at day 4 (a hollow
sphere of cells with bulge of
inner cell mass)
Travels to and implants in
uterus
Characterized by rapid and
methodical cell division
Stage where identical twins
usually originate

Question 6

Stage 2: Embryonic Stage
(2-8 weeks)

Answer 6

Development of major organs and basic
anatomy
*After implantation, the inner
cell mass becomes the
embryo and the rest of the
cells develop into its support
system.

Question 7

The Embryo

Answer 7

Neural tube =U-shaped groove formed
from top layer of differentiated cells in
embryo
Eventually becomes
brain and the spinal cord

Question 8

The Embryo Support System

Answer 8

Placenta: permits the exchange of materials between the bloodstream of the fetus and that of the mother
Umbilical cord:
contains blood vessels
that travel between the placenta
and developing organism
*Amniotic Sac: Protective Buffer

Question 9

Stage 3: Fetal Stage
(9 weeks - birth)

Answer 9

Formally starts when differentiation of major organs has occurred (organism now called fetus)
Characterized by rapid development
Organs more differentiated and begin working
Interconnections between body parts become more complex and integrated
By 20 weeks, facial expressions are present!

Question 10

Cephalocaudal Development
(head to toe)

Answer 10

changes in size of head
relative to body

Question 11

Fetal Behavior

Answer 11

By 12 weeks after gestation,
most of the movements that
will be present at birth have
appeared
*Prenatal to postnatal continuity!!!
(Important!)
*Movement in utero = practice for
external functions (hiccups, swallowing, moving, waking, fetal ‘breathing’)

Question 12

Fetal Sensory Experience

Answer 12

Not many visual experiences - REM sleep
Lots of opportunity for tactile stimulation
Fetuses have a preference for certain
tastes before birth (i.e., saccharin)
These preferences last until childhood;
more pronounced in breast-fed infants
They prefer smells associated with foods
that the mother has eaten.

Question 13

Fetal Learning

Answer 13

DeCasper & Spence (1986):
Newborn infants recognize rhymes
and stories presented before birth
*Newborns also prefer familiar smells, tastes, and sound
patterns from womb
‐amniotic fluid
‐long-lasting taste preferences

Question 14

Protection of Developing Child

Answer 14

Placental membrane= barrier against some
(not all!) toxins/infectious agents
Amniotic sac= membrane filled with fluid in
which infant floats, provides protective buffer

Question 15

Teratogens

Answer 15

Environmental agents that have potential to cause
harm during prenatal development
Timing is crucial factor in severity of effects of these potentially harmful agents
Many agents cause damage only if
exposure occurs during a sensitive period in
development

Question 16

Famous Teratogens:
Thalidomide

Answer 16

Marketed from 1957-1961
Goal was to cure morning sickness
Big issue: Limb abnormalities in children; some
deaths

Question 17

Some Environmental Hazards
to Fetus or Newborn

Answer 17

Drugs

Antidepressants

Opioids (Vicodin, Percocet, Oxycodone, Fentanyl, heroin)

Marijuana

Nicotine
Cigarette smoking
Secondhand smoke
E-cigarettes

Alcohol
Environmental pollutants

Toxic metals, synthetic hormones, plastic ingredients,
pesticides, herbicides

Air and water pollution

Lead (dose–response relationship)

Question 18

Fetal alcohol spectrum
disorder (FASD)

Answer 18

when a mother’s alcohol consumption
during pregnancy affects the
fetus; can include facial
deformities, intellectual
disabilities, attention
problems, hyperactivity, and
other defects

Question 19

Maternal Factors

Answer 19

Age, nutrition, disease, and stress-level of mother have
impact on prenatal development
Infants born to girls 15 years or younger = 3 to 4 times
more likely to die before first birthday than those whose
mothers are in 20s
Inadequate supply of
specific nutrients/vitamins
(e.g., folic acid) can have
dramatic consequences
(e.g., growth of the fetal brain)
Variety of diseases including
sexually transmitted diseases
present hazards to the fetus

Question 20

Father’s Prenatal Influence

Answer 20

Relatively little research
Tobacco use
Drug use
Alcohol use
Treatment of mother
AGE!

Question 21

What is it like to be born?

Answer 21

Newborn is squeezed very tightly during birth
* Forces liquid out of lungs
* Changes head shape
Anoxia – oxygen deprivation
* Consequence of normal birth process
* Prolonged anoxia can lead to brain damage

Question 22

State of Arousal

Answer 22

Response to distress
A study found that quick response to crying results in
less crying several months later.
Another study found that ignoring crying during the
first 9 weeks reduced crying during the next 9 weeks.
Colic:excessive, inconsolable crying by a
young infant for no apparent reason
1 in 10 U.S. infants; typically ends around 3 months
No long-term effects

Question 23

Outcomes at Birth

Answer 23

Birth weight
Average newborn: 7½ pounds
Low birth weight (LBW):less than 5½ pounds
High level of medical complications; high rates of
neurosensory deficits, frequent illnesses, lower IQ scores
Very low birth weight (VLBW):less than 3.3 pounds
Premature (preterm) babies: born at 37 weeks
after conception; small for gestational age
Increase in multiple births; infertility treatment

Question 24

Outcomes at Birth

Answer 24

Long-term outcomes
Comparison statistics may confound SES with birth-
weight status.
Negative effects of birth status gradually diminish for
majority of LBW infants.
Special services and additional support may be
important.
Intervention factors
Kangaroo care
Breast milk
CCC: cuddled, caressed, and carried
Educational programs

Question 25

Infant Mortality

Answer 25

Infant mortality
Death during the first year after birth
In the United States, in 2016: 5.87 deaths
per 1000 births
Relatively rare event in the Western
industrialized world
However, rates in the United States are
among the highest in the “first world”…
Poverty and lack of health insurance are
associated with high rates of infant mortality