1. Life-Span Development
Twelfth Edition
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CHAPTER 3: PRENATAL DEVELOPMENT
AND BIRTH

2. Prenatal Development
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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

3. Prenatal Development
Germinal Period: period of development that 3
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

4. Prenatal Development
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5. Prenatal Development
Embryonic Period: development from 2 to 8 weeks 5
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

6. Prenatal Development
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7. Prenatal Development
The life support system for the embryo consists 7
of the: umbilical cord, placenta, and amnion
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

8. Prenatal Development
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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

9. Hazards to Prenatal Development
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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
 STD’s

10. Hazards to Prenatal Development
 Prescription and Non-prescription Drugs: 10
 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
 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

11. Hazards to Prenatal Development
Psychoactive Drugs: drugs that act on the nervous 11
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

12. Hazards to Prenatal Development
Alcohol: 12
 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

13. Hazards to Prenatal Development
Nicotine: 13
 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)

14. Prenatal Care
Prenatal care typically includes: 14
 Screening for manageable conditions and treatable
diseases
 Medical care
 Educational, social, and nutritional services
Centering Pregnancy: relationship-centered
program
Importance of prenatal care

15. The Birth Process
Three stages of birth: 15
 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
 Stage 2: baby’s head begins to move through dilated
cervix opening and eventually emerges from the mother’s
body
 This stage lasts approximately 45 minutes
 Stage 3: umbilical cord, placenta, and other membranes
are detached and expelled (afterbirth)

16. The Birth Process
At the time of birth, the baby is covered with a 16
protective skin grease called vernix caseosa
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

17. Methods of Childbirth
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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

18. Methods of Childbirth
 Natural childbirth: aims to reduce pain by decreasing fear and 18
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
 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

19. Methods of Childbirth
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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

20. Transition from Fetus to Newborn
Birth process is stressful for baby 20
 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

21. Transition from Fetus to Newborn
Measuring neonatal health and responsiveness: 21
 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

22. Preterm and Low Birth Weight Infants
Preterm and Small-for-Date Infants: 22
 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

23. Preterm and Low Birth Weight Infants
Causes of low birth weight:
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 Poor health and nutrition
 Cigarette smoking
 Adolescent births
 Use of drugs
 Multiple births/reproductive technology
 Improved technology and prenatal care
Possible consequences:
 Language development delays / Lower IQ scores
 Lung or liver diseases / More behavioral problems
 Learning disabilities / ADHD
 Breathing problems (asthma)
 Approximately 50% are enrolled in special education programs

24. Preterm and Low Birth Weight Infants
Some effects can be improved with: 24
 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

25. The Postpartum Period
Postpartum period lasts about six weeks or until the 25
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 pre-
pregnant size 5–6 weeks after birth
 Weight loss/return to exercise

26. % of U.S. Women: Postpartum Blues and Postpartum Depression
Postpartum blues: “Baby Blues” experienced by 70% of
symptoms appear 2 to 3 new mothers in the U.S.
days after delivery and
subside within 1 to 2 weeks Typically resolves in 1–2 weeks,
without treatment
Postpartum Depression
Excessive sadness, anxiety, and
70% despair that lasts for two weeks
or longer
Experienced by 10% of new
mothers
20% 10% Hormonal changes after birth
may play a role
May affect mother–child
interactions
No symptoms
Postpartum depression: symptoms
linger for weeks or months and
interfere with daily functioning
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27. The Postpartum Period
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Signs of postpartum depression: crying spells,
insomnia and loss of appetite
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

28. Bonding
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Bonding: the formation of a connection, especially a
physical bond, between parents and the newborn in
the period shortly after birth
 Isolationof 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