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  1. 1. Life-Span Development Twelfth Edition 1CHAPTER 3: PRENATAL DEVELOPMENT AND BIRTH
  2. 2. Prenatal Development 2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. 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. 4. Prenatal Development 4
  5. 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. 6. Prenatal Development 6
  7. 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. 8. Prenatal Development 8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. 9. Hazards to Prenatal Development 9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. 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. 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. 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. 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. 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. 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. 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. 17. Methods of Childbirth 17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. 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. 19. Methods of Childbirth 19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. 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. 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. 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. 23. Preterm and Low Birth Weight InfantsCauses of low birth weight: 23  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. 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. 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. 26. % of U.S. Women: Postpartum Blues and Postpartum DepressionPostpartum blues: “Baby Blues” experienced by 70% ofsymptoms appear 2 to 3 new mothers in the U.S.days after delivery andsubside 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 interactionsNo symptoms Postpartum depression: symptoms linger for weeks or months and interfere with daily functioning 26
  27. 27. The Postpartum Period 27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. 28. Bonding 28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