ELED 132, Child Growth and Development

1. ELED 132, Child Growth and Development Dr. Andrew Whitehead More Information at: www.esu.edu/~andrew

2. Biological Beginnings • Genetic Foundations of Child Development • Structure and Function of Genes • Genes- the basic unit of heredity • 46 Chromosomes, 23 distinct pairs – one pair from mother and one pair from father • DNA • Formation of Reproductive Cells • Gametes – male and female reproductive cells • Sperm in male – Ova in female

3. Genetic Basis of Individual Traits • Common mechanisms of genetic transmission • Alleles - genes located at the same point on corresponding (paired) chromosomes and provide instructions for a particular physical characteristic • Dominant gene – overriding gene that determines the characteristic (dark features, e.g., dark hair/ brown eyes) • Recessive gene – influencing gene, primarily when an identical gene is contained in the allele pair (light features, e.g. blonde hair/ blue eyes) • Codominance – when both genes of the allele pair, although not identical, share the influence on a physical characteristic

4. Problems in Genetic Instruction • Genetic disorders result in major physical problems and/or mental retardation • Chromosome abnormalities – uneven division of chromosomes during meiosis • 1 in 150 births may result in: • An extra chromosome • A missing chromosome • A wrongly formed chromosome • Single-gene defects - inherited from one or both parents • Common chromosomal and genetic disorders include (see Table 3-1): • Down Syndrome – extra 21st chromosome • Klinefelter Syndrome – boys only; XXY • Turner Syndrome – girls only; X chromosome, missing second • Hungington Disease (HD) • Phenylketonuria (PKU) • Sickle Cell Disease • Cystic Fibrosis (CF)

5. The Awakening of Genes • Some genes are inactive and influence development later during maturation • Canalization – tight genetic control of a certain development aspect • Basic motor skills, e.g., crawling, sitting, walking • Not canalized – most acquired skills • Reading, writing, math, social skills • Sensitive periods are critical in physical development, perceptual ability, brain development, and language acquisition • Toxic substances are particularly dangerous during prenatal development of limbs, organs, facial structures, and brain connections

6. The Blending of Heredity and Environment • Genetics are greatly influenced by environmental and personal factors: • Nutrition • Illness • Medication • Stressful events • Intensity of stimulation • Opportunities for physical activity • Personality and Intellect are the outcomes of both nature and nurture effects • Genetics affect a child’s response to the environment through three mechanisms: • Passive gene-environment relation – parents genetic tendencies correlate to the context in which they raise their children • Evocative gene-environment relation – a child’s own characteristic elicits specific responses form the environment around them • Active gene-environment relation - a child’s talent influences the environment

7. Acknowledging Nature and Nurture in Children’s Lives • Value individual differences among children and adolescents • The environment (along with genetics) influences every aspect of development • Intervene when children display intellectual, social, and emotional struggles • Encourage children to select activities that promote growth and development

8. Period of the Embryo (week 2 - 8) • Major body structures and life support are formed • Placenta grows - forms umbilical cord • Provides food, liquid, oxygen • Removes waste • Secretes hormones to sustain embryonic growth • Embryo develops • Head and heart • From top to bottom (head first, feet last) • From inside to outside (torso before limbs, arms and legs before hands and feet) • Neural tube (eventual brain and spinal cord) forms • Internal organs appear • Buds and limbs develop • Fingers and toes are recognizable at 8 weeks

9. Period of the Fetus (week 9 to birth) • Grows in size and weight, sensory abilities, brain structures and organs needed for survival • Third month • Head is large, slows growth • Eyes move into place; increasingly human-looking • Genitalia form • Reflex and muscular movement (although not felt) • Four month • Rapid growth in length (height) • Slow weight increase • Hair growth on head and eyebrows • Fifth month • Rapid growth in length (height) continues • Fine hair growth covers body • Movement is felt by mother • Sixth month (avg. weight 1 lb. 13 oz.) • Skin is red and wrinkled; body is lean; fingernails are evident • Development of respiratory and central nervous system continues • Seventh month (avg. weight 2 lb. 14 oz.) • Eyes open; eyelashes and toenails form • Body fills out • Eighth month (avg. weight 4 lb. 10 oz.) • Skin becomes pink and smooth; fat growths beneath skin • Testes descend (in males)

10. Medical Care • Preparing for pregnancy (starts before conception) • Watch diet • Take approved vitamin supplements • Exercise • Avoid alcohol and drugs (includes OTC meds) • Other factors • Hypertension or diabetes • Under age 17 = low birth weight • Mothers over 35 and fathers over 40 = higher risk for genetic problems • Seek a genetic counselor

11. Avoiding Harmful Substances • Teratogens – potentially harmful substance that can cause problems during prenatal development • Prescription or non-prescription drugs or • Infectious agents, e.g., rubella, syphilis, HIV • Environmental chemicals, e.g., lead or polychlorinated biphenyls • Alcohol causes FAS - (Fetal Alcohol Syndrome) delayed physical and motor development, facial abnormalities, mental retardation, impulsivity and other behavior problems, learning disabilities or minor physical problems • Nicotine - low birth weight and occasionally miscarriage • Drugs – various problems • HIV and AIDS – Delayed motor skills, language, and cognitive development; major health risks and problems • Maternal anxiety also contributes to low birth weight, irritability, and problems with attention and dealing with negative emotional issues

12. Sensitive Periods in Prenatal Development

13. Examples of Risk Factors for Healthy Neurological Development

14. Implementing Medical Procedures • Ultrasonography – detects age, major abnormalities, and number/gender of fetuses • CVS (Chorionic Villus Sampling) for high risk pregnancies • Invasive procedure performed at 7-12 weeks • Needle inserted into abdomen or tube guided through cervix to collect chorionic villi (blood vessels) • Used to detect chromosomal abnormalities • May damage embryo/fetus arm or leg; cause miscarriage (rare) • Amniocentesis – • Needle inserted into abdomen; fluid drawn from uterus • Fetal protein and cells analyzed for neural tube defects or chromosomal abnormalities • May cause fetal trauma, infection, or miscarriage

15. Supporting Parents, Protecting Babies • Encourage women to evaluate their health before pregnancy • Remind sexually active women also to be health conscious • Encourage new mothers to seek medical care • Remind expectant mothers to avoid teratogens • Encourage them to relax and speak their minds • Talk to fathers about their experiences and feelings • Advise parents about appropriate care when children have been exposed to teratogens • Intervene when mothers continue substance abuse after birth

16. Birth of the Baby • Preparation for Birth • Child birth classes provide: • Relaxation and breathing techniques for focus, pain management, reduction of fear, effective use of muscles during birth • Support from a birth coach (spouse, partner, friend, family) • Basic education about physiology and mechanics of delivery, positions, pain options, and medical interventions • Support for decisions about where and when birth may occur • Hospitals • Community birth centers • Home settings

17. The Birth Process • Typically at 38 - 40 weeks, both a mother’s hormonal changes and the maturation of the fetus trigger birth • Braxton Hicks contractions exercise the uterine muscles without opening the cervix • 95% head-downward position • Cesarean delivery may result: • Breech position – butt or legs first • Sideways position – shoulder first • Several days before labor, the mother experiences • Decent of baby into pelvis • Rush of energy • Weight loss of 1 to 4 pounds from hormonal changes • Vaginal secretions • Difficulty sleeping

18. The Birth Process (cont’d) • First stage of labor • Regular contractions and widening of cervix to 10 cm (4”) dilat. • Pelvis and back pain • First time mothers 12 - 16 hours; 6 - 8 hours for second birth or more • Contractions become stronger and longer • Second stage of labor • Cervix is fully dilated, baby proceeds down birth canal • Baby is born • This process may last ½ to 2 hours (first baby) • Third stage of labor • Afterbirth expelled by uterus (placenta and fetal membranes) • Usually baby is alert, looking around the room

19. Complications and Interventions • Midwives, coaches, and medical staff may relieve pain without using meds • Warm whirlpool • Massage • Music • Hypnosis • Biofeedback • Visual images of the cervix opening • Physicians may use meds and interventions, e.g., • Analgesics • Epidural analgesia (spinal injection) • Anesthetics • Opioids (a.k.a. narcotics) • Induced labor using Pitocin • Cesarean delivery (30%) • Fetal distress • Mother’s health problems • Failure for labor to progress • Birth canal infections • Presence of multiple babies

20. Babies at Risk • Premature infant – babies are considered premature if born before the end of week 37 • Premature labor is triggered by • Infection, multiple gestations (twins or triplets), fetus abnormalities, death of fetus, uterine or cervical abnormalities, serious disease in mother • Seriously premature babies suffer from • Breathing problems, anemia, brain hemorrhages, feeding problems, instability in temperature • Babies born small for date are at risk for • Neurological deficiencies, structural problems with body parts, difficulty with breathing and vision • Low birth size and weight after sufficient time in the uterus is often caused by exposure to teratogens or chromosomal abnormalities

21. Developmental Care for Babies at Risk • Fragile infants need • Medical staff to • Reduce their exposure to noise and light • Regulate the amount of handling • Position them in a way that increases circulation • Parents to • Stay actively involved during infant care • Stay informed of the infant’s needs • Arrange a proper activity schedule to ensure sleep and rest • Cuddle and carry them often and for long periods • Swaddle them in a blanket with arms bent allowing the baby’s hands to reach their mouth for sucking • Massage them • Stay informed through early childhood development

22. Enhancing Caregivers’ Sensitivity to Newborn Infants • Talk about the baby’s sensations (physiological detection of environmental stimuli) and perceptions (interpretation of sensations) • Point out the newborn’s states of arousal (sleepiness and wakefulness) and reflexes (automatic motor response to stimuli) experienced throughout the day • Encourage parents to become aware of their baby’s responses to certain stimuli • Suggest different types of soothing techniques, i.e., listening to a clothes dryer, nursing, sleeping on father’s chest, riding in a car • Model sensitivity to baby’s interaction preferences • Teach parents how to perform care-taking functions, e.g., feeding, bathing, diaper changing, and proper carrying or holding • Offer continued support for parents of fragile infants