Chapter 3: Lecture Outline 1
PSYC 211: Katrina’s Lecture Outline
Chapter 3: Prenatal Development, Birth, and the Newborn Baby
I. PRENATAL DEVELOPMENT
B. Period of the Zygote
1. This period lasts about 2 weeks
2. The Placenta and Umbilical Cord
a. The placenta brings the embryo’s and mother’s blood close together.
b. The umbilical cord delivers blood with nutrients and removes waste products.
C. Period of the Embryo
1. The period of the embryo, from the second through the eighth week of pregnancy, is when the
groundwork is laid for all body structures and internal organs.
2. Last Half of the First Month
a. The heart begins to pump blood, and the muscles, backbone, ribs, and digestive tract
3. The Second Month
a. The eyes, ears, nose, jaw, and neck form. Tiny buds become arms, legs, fingers, and
b. At 7 weeks, production of neurons (nerve cells that store and transmit information)
D. Period of the Fetus
1. The period of the fetus, from the ninth week to the end of pregnancy, is the “growth and
finishing” phase, when the organism increases rapidly in size.
2. The Third Month
a. The organs, muscles, and nervous system become organized and connected.
b. Body position changes occur as often as 25 times per hour.
c. Prenatal development is sometimes divided into three equal time periods called
3. The Second Trimester
a. By the middle of the second trimester (between 17 and 20 weeks), the mother can
feel the movements of the fetus.
b. At the end of the second trimester, most of the brain’s neurons are in place and they
begin forming synapses, or connections, at a rapid pace.
c. The fetus has new behavioral capacities
4. The Third Trimester
a. The age of viability, between 22 and 26 weeks, is the point at which the baby can first
survive if born early.
b. The cerebral cortex enlarges, and as neural connectivity and organization improve,
the fetus spends more time awake.
c. Responsiveness to stimulation, including pain, increases, and the fetus begins to
distinguish the tone and rhythm of different voices and sounds.
d. The fetus receives antibodies from the mother’s blood. Chapter 3: Lecture Outline 2
II. PRENATAL ENVIRONMENTAL INFLUENCES
1. A teratogen is any environmental agent that causes damage during the prenatal period.
a. Larger doses of teratogens over longer time periods usually have more negative
b. The effects of teratogens vary with the organism’s age at the time of exposure.
(1) Sensitive period
(2) Embryonic period
c. The effects of teratogens illustrate bidirectional influences between child and
2. Prescription and Nonprescription Drugs
a. Thalidomide, a sedative used in the 1960s
b. Diethylstilbestrol (DES), widely prescribed between 1945 and 1970 to prevent
c. Accutane (isotretinoin), prescribed to treat severe acne
d. High doses of caffeine increase the risk of low birth weight.
e. Persistent intake of antidepressant medication is linked to an elevated incidence of
premature delivery and birth complications.
3. Illegal Drugs
a. Babies born to users of cocaine, heroin, or methadone during pregnancy are at risk
for prematurity, low birth weight, physical defects, breathing difficulties, and death
around the time of birth.
b. Throughout the first year, heroin- and methadone-exposed infants are less attentive
to the environment than nonexposed babies, and their motor development is slow.
c. Prenatal exposure to cocaine may cause lasting difficulties in some babies, including
physical defects, but some investigations find no major negative effects of prenatal
d. Researchers have linked prenatal marijuana exposure to smaller head size and
attention, memory, and academic difficulties.
a.. Effects of smoking during pregnancy include low birth weight and increased chances
of miscarriage, prematurity, blood vessel abnormalities, and asthma and cancer later in
b. “Passive smoking” is also related to low birth weight, infant death, and possible long-
term attention, learning, and behavioral problems.
5. Alcohol: Fetal alcohol spectrum disorder (FASD) refers to the range of physical, mental, and
behavioral outcomes caused by prenatal alcohol exposure.
a. Fetal alcohol syndrome (FAS), distinguished by slow physical growth, three facial
abnormalities, and brain injury, typically occurs when a woman drinks heavily
b. Partial fetal alcohol syndrome (p-FAS) is a related condition seen in children of
mothers who drank alcohol in smaller quantities. These children display some facial
abnormalities and brain injury.
c. Alcohol-related neurodevelopmental disorder (ARND), in which some mental
functioning is impaired, results from less pervasive alcohol exposure.
d. Mental impairment associated with all the FASD diagnoses is permanent. Chapter 3: Lecture Outline 3
6. Radiation: Radiation exposure can cause miscarriage, an underdeveloped brain, physical
deformities, and slow physical growth.
7. Environmental Pollution
a. Prenatal mercury exposure from maternal seafood diets
b. Exposure to polychlorinated biphenyls (PCBs)
c. High levels of prenatal lead exposure are linked to prematurity, low birth weight,
brain damage, and a variety of physical defects. Low levels are associated with poorer
mental and motor development
d. Prenatal exposure to dioxins
8. Infectious Disease
(1) Maternal rubella can cause a wide variety of defects, including organ
damage, especially when it occurs during the embryonic period.
(2) Between 20 and 30 percent of untreated pregnant women infected with the
human immunodeficiency virus (HIV), which can lead to acquired immune
deficiency syndrome (AIDS), pass the deadly virus to the developing organism.
b. Bacterial and Parasitic Diseases: Among the most common is toxoplasmosis
B. Other Maternal Factors
1. Nutrition: A healthy diet helps ensure the health of the mother and baby.
a. Prenatal malnutrition
b. Providing pregnant women with adequate food as well as vitamin–mineral
enrichment has a substantial impact on the health of newborns.
c. Prenatal malnutrition is highest in poverty-stricken regions but is not limited to
2. Emotional Stress
a. Intense anxiety during pregnancy, especially during the first two trimesters, is
associated with miscarriage, prematurity, low birth weight, and colic.
b. Maternal stress hormones cross the placenta, causing a dramatic rise in fetal stress
c. Excessive fetal stress may permanently alter fetal neurological functioning
3. Rh Factor Incompatibility
a. Rh factor incompatibility occurs when a mother is Rh-negative (lacks the Rh blood
protein) and the infant inherits the Rh-positive blood type from the father; however, a
vaccine can prevent Rh incompatibility in most cases.
b. If Rh blood incompatibility does occur, it can result in mental retardation, miscarriage,
heart damage, and infant death.
4. Maternal Age
a. Women who delay childbearing until their thirties or forties face increased risk of
infertility, miscarriage, and babies born with chromosomal defects. However, research
shows that healthy women in their thirties have about the same rates of pregnancy
complications as those in their twenties. Thereafter, complication rates increase.
b. A teenager is physically capable of supporting a pregnancy. Higher rates of problems
seen in infants born to teenagers are related to the lack of access to medical care,
stress, poor nutrition, and health problems associated with poverty.
C. The Importance of Prenatal Health Care Chapter 3: Lecture Outline 4
1. Early and sustained prenatal care helps ensure the health of the mother and fetus
2. In addition to financial hardship, situational barriers and personal barriers can keep mothers
from seeking early prenatal care.
A. The Stages of Childbirth
1. Dilation and effacement of the cervix is the longest stage of labor
2. Delivery of the baby, during which the mother squeezes and pushes with her abdominal
3. Delivery of the placenta, the end of labor, results in the placenta separating from the uterine
wall and being delivered
B. The Baby’s Adaptation to Labor and Delivery: Stress hormones caused by the force of the contractions
send extra blood to the brain and heart, help prepare the baby to breathe, and arouse the infant into
C. The Newborn Baby’s Appearance
1. The average newborn is 20 inches long and 71⁄2 pounds in weight; boys tend to be slightly
longer and heavier than girls.
2. The head is large in comparison to the trunk and legs, which are short and bowed.
3. The round faces, chubby cheeks, large foreheads, and big eyes of newborn babies make adults
feel like picking them up and cuddling them.
D. Assessing the Newborn’s Physical Condition: The Apgar Scale
1. Infants who have difficulty making the transition to life outside the uterus must be given help
2. The Apgar Scale is used to assess the infant’s phy