Chapter 4: Prenatal Development and Birth

Chapter 4: Prenatal Development and Birth

Total Teaching Package Outline

Lecture Outline / Resource References
Prenatal Development and Birth / PowerPoint Presentation: See www.mhhe.com
Cognitive Maps: See Appendix A
Prenatal Development
·  The Course of Prenatal Development
-The Germinal Period
-The Embryonic Period
-The Fetal Period
·  Cultural Beliefs about Pregnancy / LO1
OHT 23, 24, 31, OHT 38 & IB, OHT 48 & IB:
Prenatal Development
LS1: Technology and Images of Prenatal Dev.
F/V: Developmental Phases Before and After Birth
F/V: Invasion of the Embryo
F/V: Prenatal Development
F/V: Pregnancy and Birth
F/V: Psychological Development Before Birth
F/V: Reproduction: Fetal Development
WS: The Visible Embryo
LO2
LO3
LO4
CA1: Reproductive Double Standards for Men
and Women
PA1: In a Family Way
Teratology and Hazards to Prenatal Development
·  Exploring Teratology
·  Prescription and Nonprescription Drugs
·  Psychoactive Drugs
- Alcohol
-Nicotine
-Illegal Drugs
·  Environmental Hazards
·  Other Maternal Factors
-Infectious Diseases
-Nutrition
-Emotional States and Stress
-Maternal Age
·  Paternal Factors
·  Prenatal Care
·  Positive Prenatal Development / WS: Teratology Society
LS2: Principles of Teratogenic Effects
LO5
OHT39 & IB: Drug Use during Pregnancy
LS3: Dangers of Drug Use during Pregnancy
CA2: Court’s Treatment of Substance
Abusing Pregnant Women
F/V: Pregnancy and Substance Abuse
LS4: Birth Defects Are Too Often Blamed on
Alcohol
CA3: Fetal Alcohol Syndrome Quiz
F/V: David with Fetal Alcohol Syndrome
F/V: Fetal Alcohol Syndrome and Other Drug
Use During Pregnancy
F/V: Fetal Alcohol Syndrome: Life Sentence
RP1: Why Do Some Pregnant Women Drink,
Smoke, or Use Drugs?
F/V: Unborn Addicts
LO6
F/V: AIDS Babies
WS: Caffeine in Pregnancy
LO7
OHT32: Mothers with Late or No Prenatal Care
Birth
·  Exploring the Birth Process
-Stages of Birth
-The Fetus/Newborn Transition
-Childbirth Strategies
·  Preterm Infants and Age-Weight
Considerations
-Preterm and Low-Birthweight Infants
-Long-Term Outcomes for Low-Birthweight Infants
·  Measures of Neonatal Health and Responsiveness / PA2: Oh, the Pain!
LO8
LO9
LO10
F/V: Birth without Violence
F/V: Contemporary Childbirth
F/V: A Human Life Emerges
F/V: The Process of Birth
WS: Childbirth
LO11
OHT40 & IB: Percentage of LBW Infants
WS: Evidence-Based Ethics and the Care of
Premature Infants
LO12
F/V: Brazelton Neonatal Behavioral
Assessment Scale: An Introduction
WS: Apgar Scoring
The Postpartum Period
·  What Is the Postpartum Period?
·  Physical Adjustments
·  Emotional and Psychological Adjustments

·  Bonding

/ LO13
RP2: Fatherhood
F/V: The Newborn: Development and Discovery
WS: Postpartum Depression
CA4: Reasons to Have Children or Not
F/V: The Newborn: Development and Discovery

Review

/ PA3: The Pitter Patter of Little Feet
CA5: Critical Thinking Multiple-Choice
CA6: Critical Thinking Essays
F/V: The Mind: Development

Chapter Outline

PRENATAL DEVELOPMENT

The Course of Prenatal Development

·  Prenatal development is divided into three periods:

The Germinal Period

·  The germinal period takes place in the first 2 weeks after conception. It includes the creation of the zygote, continued cell division, and the attachment of the zygote to the uterine wall.

·  The blastocyst is the inner layer of cells that develop into the embryo.

·  The trophoblast is the outer layer of cells that develops and provides nutrition and support for the embryo.

·  Implantation, attachment of the zygote to the uterine wall, occurs 10 days after conception.

The Embryonic Period

·  The embryonic period occurs from 2 to 8 weeks after conception.

·  The rate of cell differentiation intensifies, support systems for the cells form, and organs appear.

·  Endoderm, inner layer of cells, develops into the digestive and respiratory systems.

·  Ectoderm, outermost layer of cells, becomes the nervous system, sensory system, and skin.

·  Mesoderm, middle layer of cells, becomes the circulatory system, bones, muscles, excretory system, and reproductive system.

·  Life-support systems for the embryo mature and develop rapidly:

·  The placenta is a life-support system that consists of a disk-shaped group of tissues in which small blood vessels from the mother and the offspring intertwine but do not join.

·  The umbilical cord is a life-support system, containing two arteries and one vein, that connects the baby to the placenta.

·  The amnion is a bag that contains clear fluid in which the developing embryo floats.

·  Organogenesis is the process of organ formation that takes place during the first 2 months of prenatal development.

The Fetal Period

·  The fetal period begins 2 months after conception and lasts for 7 months, on average.

·  Growth and development continue their dramatic course and organ systems mature to the point at which life can be sustained outside of the womb.

Cultural Beliefs about Pregnancy

·  Specific actions in pregnancy are often determined by cultural beliefs (whether pregnancy is viewed as a medical condition or a natural occurrence).

·  Certain behaviors (prenatal care) are expected if pregnancy is viewed as a medical condition.

Teratology and Hazards to Prenatal Development

Exploring Teratology

·  A teratogen is any agent that causes a birth defect.

·  Teratology is the field of study that investigates the causes of birth defects.

·  Sensitivity to teratogens begins about 3 weeks after conception. The probability of a structural defect is greatest early in the embryonic period, during organogenesis.

·  Exposure during the fetal period usually is more likely to stunt growth or cause problems in the way organs function.

Prescription and Nonprescription Drugs

·  In the 1960s, thalidomide was taken by some women in order to reduce morning sickness and caused limb malformation in some of the developing fetuses.

·  Prescription drugs, such as antibiotics, some antidepressants, estrogen, and Accutane (acne medicine) have teratogenic effects.

·  Nonprescription drugs, such as diet pills, aspirin, and caffeine have potential teratogenic effects.

Psychoactive Drugs

·  Psychoactive drugs are drugs that act on the nervous system to alter states of consciousness, modify perceptions, and change moods.

Alcohol

·  Fetal alcohol syndrome (FAS) is a cluster of abnormalities that appears in the offspring of mothers who drink alcohol heavily during pregnancy. The abnormalities include facial deformities, and defective limbs and heart. Most of these children are below average in intelligence, and some are mentally retarded.

·  When pregnant women drink moderately (1-2 drinks a day) negative effects on their offspring have been found.

Nicotine

·  Cigarette smoking by pregnant women can adversely influence prenatal development. There is a higher incidence of preterm births and lower birthweights, and a higher chance of fetal and neonatal deaths.

Cocaine

·  The most consistent finding is that cocaine exposure during prenatal development is associated with reduced birthweight, length, and head circumference. Information-processing deficits have been found as well.

·  Caution is necessary when interpreting these findings as poverty, malnutrition, etc. may contribute to the negative effects found.

Marijuana

·  Marijuana use during pregnancy has been associated with increased tremors and startles in newborns and poor verbal and memory development at 4 years of age.

Heroin

·  Young infants exposed prenatally to heroin are addicted and show withdrawal symptoms at birth. Behavioral problems and attention deficits continue to be present.

Environmental Hazards

·  Potential environmental hazards include radiation, environmental pollutants, toxic wastes, prolonged exposure to heat in saunas and hot tubs, and low-level electromagnetic radiation from computer monitors.

Other Maternal Factors

Infectious Diseases

·  Maternal diseases and infections can produce defects by crossing the placental barrier or they can cause damage during the birth process.

·  Rubella (German measles), syphilis, genital herpes, and human immunodeficiency virus (HIV) can all affect the developing organism.

Nutrition

·  A developing fetus depends completely on its mother for nutrition, which comes from the mother’s blood. The total number of calories and appropriate levels of protein, vitamins, and minerals are important factors.

·  The lack of folic acid is linked to neural tube defects in the offspring (spina bifida).

Emotional States and Stress

·  Maternal anxiety and stress are linked with less than optimal prenatal and birth outcomes (premature delivery).

Maternal Age

·  Two age periods may lead to problems for the offspring’s development: adolescence (higher incidence of premature infants and infant mortality) and mothers of age 30 or older (infertility and increased risk for Down syndrome).

Paternal Factors

·  Men’s exposure to lead, radiation, certain pesticides, and petrochemicals can cause abnormalities in sperm that lead to miscarriage or diseases. Father’s smoking during the mother’s pregnancy can cause newborns to be lighter at birth and increase the risk of childhood cancers.

Prenatal Care

·  Prenatal care varies extensively, but usually involves medical-care services with a defined schedule of visits. Screening for treatable conditions, education about pregnancy, labor and delivery, and newborn care are included.

Positive Prenatal Development

·  Most pregnancies proceed without negative outcomes. It is important for prospective mothers and pregnant women to avoid the vulnerabilities that teratogens produce.

BIRTH

Exploring the Birth Process

Stages of Birth

·  The birth process occurs in three stages:

·  The first stage lasts about 12 to 24 hours for a woman having her first child. The cervix dilates to about 4 centimeters due to uterine contractions.

·  The second stage, which lasts approximately 11/2 hours, begins when a baby’s head moves through the cervix and ends with the baby’s complete emergence.

·  The third stage, which lasts a few minutes, is called afterbirth at which time the placenta, umbilical cord, and other membranes are detached and expelled.

The Fetus/Newborn Transition

·  Anoxia is the condition in which the fetus/newborn has an insufficient supply of oxygen due to the placenta and umbilical cord being compressed during uterine contractions. Anoxia can cause brain damage.

·  Hormones, adrenaline and noradrenalin, are secreted to protect the fetus against stress.

Childbirth Strategies

·  Childbirth Setting and Attendants

·  Most births in the U.S. take place in hospitals with physicians in attendance. Many women have the baby’s father or a birth coach in the room during delivery.

·  In many countries, the birth is attended by a doula, a caregiver who provides continuous physical, emotional, and educational support for the woman before, during, and after childbirth.

Methods of Delivery

·  Three basic kinds of drugs are used for labor:

·  Analgesics (tranquilizers, barbiturates, and narcotics) relieve pain.

·  Anesthesia is used in late first-stage labor and during expulsion of the baby to block sensation in an area of the body or to block consciousness.

·  An epidural block is regional anesthesia that numbs the body from the waist down.

·  Oxytocics are synthetic hormones that are used to stimulate contractions.

·  The current trend is for women to use some medication during delivery, but to keep it to a minimum and to broadly educate the pregnant woman regarding labor medication.

·  Natural childbirth was developed in 1914 by an English obstetrician, Grantley Dick-Read. It attempts to reduce the mother’s pain by decreasing her fear through education about childbirth and by teaching her to use breathing methods and relaxation techniques during delivery.

·  Ferdinand Lamaze developed prepared childbirth. This strategy is similar to natural childbirth but includes a special breathing technique to control pushing in the final stages of labor.

·  In a cesarean delivery, the baby is removed from the mother’s uterus through an incision made in her abdomen. A cesarean section is often performed if the baby is in a breech position, which causes the baby’s buttocks to be the first part to emerge from the vagina.

Preterm Infants and Age-Weight Considerations

Preterm and Low-Birthweight Infants

·  Full-term infants have grown in the womb for 38 to 42 weeks between conception and delivery.

·  Preterm and low-birthweight infants are considered high-risk.

·  A preterm infant is one who is born prior to 38 weeks after conception.

·  A low-birthweight infant is born after a regular gestation period of 38 to 42 weeks but weighs less than 5 1/2 pounds. The number of low-birthweight babies has increased in the last two decades (adolescents having babies, drug use, and poor nutrition).

Long-Term Outcomes for Low-Birthweight Infants

·  Although most low-birthweight infants are normal and healthy, as a group they have more health and developmental problems than normal-birthweight infants do.

·  The number and severity of these problems increases as birthweight decreases (brain damage, cerebral palsy, lung or liver disease, learning disability, attention deficit disorder, asthma).

Measures of Neonatal Health and Responsiveness

·  The Apgar Scale is a method widely used to assess the health of newborns at 1 and 5 minutes after birth. The Apgar Scale evaluates infants’ heart rate, respiratory effort, muscle tone, body color, and reflex irritability.

·  More thorough assessments can be made with the Brazelton Neonatal Behavioral Assessment Scale, performed within 24-36 hours after birth to evaluate the newborn’s neurological development, reflexes, and reactions to people.

THE POSTPARTUM PERIOD

What Is the Postpartum Period?

·  The postpartum period is the period after childbirth or delivery. It is a time when the woman’s body adjusts, both physically and psychologically, to the process of childbearing. It lasts for about 6 weeks or until the body has completed its adjustment and has returned to a prepregnant state.

Physical Adjustments

·  Fatigue is common and can undermine the new mother’s sense of well-being and confidence in her ability to cope with a new baby and a new family life.

·  Involution is the process by which the uterus returns to its prepregnant state (5-6 weeks).

Emotional and Psychological Adjustments

·  Common maternal emotional fluctuations may be due to a number of factors: hormonal changes, fatigue, inexperience or lack of confidence with newborns, or extensive caregiving demands.

·  The following signs may indicate a need for professional counseling for postpartum adaptation: excessive worrying, depression, extreme changes in appetite, crying spells, and insomnia.

·  Paternal reactions may include jealousy regarding the woman’s attention to the baby.

Bonding

·  Bonding is the occurrence of close contact, especially physical, between parents and newborn in the period shortly after birth.