Life-Span Development Twelfth Edition

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 ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

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 ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

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 ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

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 ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

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 ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

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 ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

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 ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

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 ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

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 ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

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 ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

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 ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

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) ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

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 ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

Hazards to Prenatal Development • Environmental hazards: • Radiation • Environmental pollutants and toxic wastes • Maternal Diseases: • Sexually transmitted diseases (syphilis, genital herpes, AIDS) • Rubella • Diabetes ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

Hazards to Prenatal Development • Maternal factors: • Maternal diet and nutrition • Maternal age • Emotional states and stress • Paternal factors: • Exposure to teratogens • Paternal age ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

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 ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

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 • 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) ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

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 ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

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 ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

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 ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

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 ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

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 ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

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 ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

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 ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

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 ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

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 ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

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 ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

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 ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

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 pre-pregnant size 5–6 weeks after birth • Weight loss/return to exercise ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

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 Depression • Excessive 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 ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

70% 20% 10% Percentage of U.S. Women Who Experience Postpartum Blues and Postpartum Depression Postpartum blues: symptoms appear 2 to 3 days after delivery and subside within 1 to 2 weeks No symptoms Postpartum depression: symptoms linger for weeks or months and interfere with daily functioning ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

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 ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

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 ©2009 The McGraw-Hill Companies, Inc. All rights reserved.

Life-Span Development Twelfth Edition