Transcript Santrock Chapter 3

Life-Span Development
Twelfth Edition
C H A P T E R 3 : P R E N ATA L
D E V E L O P M E N T A N D B I RT H
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Prenatal Development
 Conception occurs when a single sperm cell from the
male unites with an ovum (egg)
 Prenatal development is divided into 3 periods and lasts
approximately 266-280 days:

Germinal period: first 2 weeks after conception, zygote created

Embryonic period: occurs from 2 to 8 weeks after conception

Fetal period: begins 2 months after conception and lasts until
birth
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Prenatal Development
 Germinal Period: period of development that
takes place the first two weeks after conception
 Rapid
cell division by the zygote
 Blastocyst: group of cells after about 1 week
 Trophoblast: outer layer of cells that later provides
nutrition and support for the embryo
 Implantation: attachment of the zygote to the uterine
wall; occurs 10 to 14 days after conception
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Prenatal Development
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Prenatal Development
 Embryonic Period: development from 2 to 8 weeks
after conception
 Begins
when blastocyst attaches to uterine wall
 Mass of cells is now called an embryo
 Three layers of cells: endoderm, mesoderm, and ectoderm
 Amnion: a bag that contains a clear fluid (amniotic fluid)
in which the embryo floats
 Umbilical Cord: connects the baby to the placenta
 Placenta: group of tissues containing mother and baby’s
intertwined blood vessels
 Organogenesis: process of organ formation during the first
two months of prenatal development
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Prenatal Development
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Prenatal Development
 Fetal Period: development from two months after
conception to birth
 Rapid
growth and change
 Viability: the age at which a fetus has a chance of
surviving outside the womb
 Currently
24 weeks; changes with advances in medical
technology
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Prenatal Development
 The Brain:
 Babies
have approximately 100 billion neurons (nerve
cells) at birth
 Architecture
of the brain takes shape during the first two
trimesters
 Increases in connectivity and functioning occur from the
third trimester to 2 years of age
 Neural
tube develops 18 to 24 days after conception
 Anencephaly
 Spina
bifida
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Prenatal Development
 The Brain:
 Neurogenesis:
the generation of new neurons
 Begins
at fifth prenatal week and continues throughout
prenatal period
 Neuronal
migration: cells move outward from their
point of origin to their appropriate locations
 Occurs
approximately 6 to 24 weeks after conception
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Hazards to Prenatal Development
 Teratogen: any agent that can cause a birth defect or
negatively alter cognitive and behavioral outcomes
 Drugs
(prescription, nonprescription)
 Incompatible blood types
 Environmental pollutants
 Infectious diseases
 Nutritional deficiencies
 Maternal stress
 Advanced age of parent
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Hazards to Prenatal Development
 Severity of damage to the unborn depends on:
 Dose
 Genetic
susceptibility
 Time of exposure
 Critical
period: a fixed time period during which certain
experiences or events can have a long-lasting effect on
development
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Hazards to Prenatal Development
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Hazards to Prenatal Development
 Prescription and Non-prescription Drugs:
 Many
women are given drugs while pregnant
 Some
are safe; some can cause devastating birth defects
 Known
prescription teratogens include antibiotics,
some antidepressants, some hormones, and Accutane
 Non-prescription teratogens include aspirin and diet
pills
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Hazards to Prenatal Development
 Psychoactive Drugs: drugs that act on the nervous
system to alter states of consciousness, modify
perceptions, and change moods
 Includes
caffeine, alcohol, nicotine
 Caffeine:
 small risk of miscarriage and low birth weight for those
consuming more than 150 mg. daily
 Increased risk of fetal death for those consuming more
than 300 mg. daily
 FDA recommends not consuming caffeine or consuming it
sparingly
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Hazards to Prenatal Development
 Alcohol:
 Fetal
alcohol syndrome: abnormalities in newborn due to
mother’s heavy use of alcohol in pregnancy
 Facial
deformities
 Defective limbs, face, heart
 Most have below-average intelligence; some are mentally retarded
 Even
light to moderate drinking during pregnancy has
been associated with negative effects on the fetus
 FDA recommends no alcohol consumption during
pregnancy
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Hazards to Prenatal Development
 Nicotine:
 Maternal
smoking can negatively influence prenatal
development, birth, and postnatal development
 Associated with:
 Preterm
births and low birth weight
 Fetal and neonatal death
 Respiratory problems
 SIDS (sudden infant death syndrome)
 ADHD (attention deficit hyperactivity disorder)
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Hazards to Prenatal Development
 Illegal drugs that harm during pregnancy:
 Cocaine
 Methamphetamine
 Marijuana
 Heroin
 Incompatible blood types (Rh factor)
 Can
cause mother’s immune system to produce
antibodies that will attack the fetus
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Hazards to Prenatal Development
 Environmental hazards:
 Radiation
 Environmental
pollutants and toxic wastes
 Maternal Diseases:
 Sexually
transmitted diseases (syphilis, genital herpes,
AIDS)
 Rubella
 Diabetes
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Hazards to Prenatal Development
 Maternal factors:
 Maternal
diet and nutrition
 Maternal age
 Emotional states and stress
 Paternal factors:
 Exposure
to teratogens
 Paternal age
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Prenatal Care
 Prenatal care typically includes:
 Screening
for manageable conditions and treatable
diseases
 Medical care
 Educational, social, and nutritional services
 Centering Pregnancy: relationship-centered
program
 Importance of prenatal care
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Percentage of U.S. Women Using Timely
Prenatal Care: 1990 to 2004
1990
2004
100
90
80
70
60
50
40
30
20
10
0
African
Non-Latino American
White women
women
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Latino
women
The Birth Process
 Three stages of birth:
 Stage 1: uterine contractions begin at 15 to 20 minutes
apart and last up to 1 minute, becoming closer and more
intense with time
 Causes
the cervix to stretch and open to about 10 cm
 This stage lasts an average of 12 to 14 hours
2: baby’s head begins to move through dilated
cervix opening and eventually emerges from the mother’s
body
 Stage
 This
stage lasts approximately 45 minutes
 Stage
3: umbilical cord, placenta, and other membranes
are detached and expelled (afterbirth)
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The Birth Process
 Childbirth Setting and Attendants:
 99% of deliveries take place in hospitals
 Home delivery or freestanding birth center
 Compared to doctors, midwives:
 Typically
spend more time than doctors counseling and educating
patients
 Provide more emotional support
 Are typically present during the entire labor and delivery process
 Doulas
provide continuous physical, emotional, and
educational support for mother before, during, and after
childbirth
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Methods of Childbirth
 Key choices involve use of medication and when
to have a cesarean delivery
 Typical pain medication:
 Analgesia:
pain relief
 Anesthesia: blocks sensation in an area of the body
(can also block consciousness)
 Epidural
block
 Oxytocics:
synthetic hormones used to stimulate
contractions
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Methods of Childbirth
 Natural childbirth: aims to reduce pain by
decreasing fear and using breathing/relaxation
techniques
 Prepared childbirth (Lamaze): special breathing
techniques; education about anatomy and
physiology
 Basic
belief is that, when information and support are
provided, women know how to give birth
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Methods of Childbirth
 Other natural techniques used to reduce pain:
 Waterbirth:
giving birth in a tub of warm water
 Massage
 Acupuncture:
insertion of very fine needles into
specific locations in the body
 Hypnosis: the induction of a psychological state of
altered attention and awareness
 Music therapy: utilizes music to reduce stress and
manage pain
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Methods of Childbirth
 Cesarean Delivery: the baby is removed from the
mother’s uterus through an incision made in the
abdomen
 Often
used if baby is in breech position or other
complications arise
 Cesareans involve a higher infection rate, longer hospital
stays, and a longer recovery time
 Rate of cesarean births has increased dramatically in
recent years
 Better
identification of complications
 Increase in overweight and obese mothers
 Extra caution by doctors to avoid lawsuits
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Transition from Fetus to Newborn
 Birth process is stressful for baby
 Anoxia: a condition in which the fetus has an insufficient
supply of oxygen
 Baby secretes adrenaline and noradrenalin, hormones that
are secreted in stressful circumstances
 Measuring neonatal health and responsiveness:
 Apgar Scale: assessed at 1 minute and 5 minutes after
birth
 evaluates
heart rate, body color, muscle tone, respiratory effort,
and reflex irritability
 10 is highest, 3 or below indicates an emergency
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Transition from Fetus to Newborn
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Transition from Fetus to Newborn
 Measuring neonatal health and responsiveness:
 Brazelton Neonatal Behavioral Assessment Scale
(NBAS):
 Typically
performed within 24–36 hours after birth
 Assesses newborn’s neurological development, reflexes, and
reactions to people and objects

Low scores can indicate brain damage or other difficulties
 Neonatal
Intensive Care Unit Network Neurobehavioral
Scale (NNNS):
 Provides
a more comprehensive analysis of newborn’s behavior,
neurological and stress responses, and regulatory capacities
 Assesses the “at-risk” infant
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Preterm and Low Birth Weight Infants
 Preterm and Small-for-Date Infants:
 Low birth weight infants weigh less than 5 ½ lbs. at birth
 Preterm infants are those born three weeks or more before full
term
 Small-for-date infants are those whose birth weight is below
normal when the length of the pregnancy is considered
 Rate of preterm births has increased
 Number of births to mothers 35 years and older
 Rates of multiple births
 Management of maternal and fetal conditions
 Substance abuse
 Stress
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Preterm and Low Birth Weight Infants
 Causes of low birth weight:
 Poor
health and nutrition
 Cigarette smoking
 Adolescent births
 Use of drugs
 Multiple births/reproductive technology
 Improved technology and prenatal care
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Preterm and Low Birth Weight Infants
 Possible consequences:
 Language development delays
 Lower IQ scores
 Brain injury
 Lung or liver diseases
 More behavioral problems
 Learning disabilities
 ADHD
 Breathing problems (asthma)
 Approximately 50% are enrolled in special education
programs
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Preterm and Low Birth Weight Infants
 Some effects can be improved with:
 Early
speech therapy
 Intensive enrichment programs
 Kangaroo care, massage therapy, and breast feeding
 Kangaroo
Care: treatment for preterm infants that involves
skin to skin contact
 Massage: research conducted by Tiffany Field
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Preterm and Low Birth Weight Infants
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The Postpartum Period
 Postpartum period lasts about six weeks or until the
mother’s body has completed its adjustment and has
returned to a nearly pre-pregnant state
 Physical Adjustments:
 Fatigue
 Hormone
changes
 Return to menstruation
 Involution: process by which the uterus returns to its prepregnant size 5–6 weeks after birth
 Weight loss/return to exercise
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The Postpartum Period
 Emotional and Psychological Adjustments:
 Emotional fluctuations are common
 “Baby Blues” experienced by 70% of new mothers in the
U.S.
 Typically
resolves in 1–2 weeks, without treatment
 Postpartum
 Excessive
Depression
sadness, anxiety, and despair that lasts for two weeks or
longer
 Experienced by 10% of new mothers
 Hormonal changes after birth may play a role
 May affect mother–child interactions
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Postpartum blues:
symptoms appear 2 to 3
days after delivery and
subside within 1 to 2 weeks
Percentage of U.S. Women Who
Experience Postpartum Blues
and Postpartum Depression
70%
20%
No symptoms
10%
Postpartum depression: symptoms
linger for weeks or months and
interfere with daily functioning
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The Postpartum Period
 A Father’s Adjustment:
 Many
fathers feel that the baby gets all of the
mother’s attention
 Parents should set aside time to be together
 Father’s reaction is improved if he has taken
childbirth classes and is an active participant in the
baby’s care
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Bonding
 Bonding: the formation of a connection, especially a
physical bond, between parents and the newborn in
the period shortly after birth
 Isolation
of premature babies and use of drugs in birth
process may harm bonding process
 Bonding may be a critical component in the child’s
development
 However,
close contact in the first few days may not be necessary
 Most
hospitals offer a rooming-in arrangement while
mother and child are in the hospital
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