Prenatal development lasts approximately 266-280 days and is divided into 3 periods: germinal, embryonic, and fetal. During this time, rapid cell division and organ formation occur. Hazards during prenatal development such as drugs, infections, and nutritional deficiencies can negatively impact the fetus. Prenatal care helps screen for conditions and provides education. Birth involves 3 stages and may be natural or utilize pain medication. Newborns are assessed using scales like Apgar to measure health. Preterm and low birth weight infants require special care.

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