Pregnancy and Prenatal Development : Lecture Week 4

1. Pregnancy and Prenatal Development: Lecture Week 4

2. Guideposts for Study • 1. What are the three stages of prenatal development, and what happens during each stage? • 2. What environmental influences can affect prenatal development?

3. Prenatal Development: Three Stages • Germinal Stage ( ) • Embryonic Stage ( ) • Fetal Stage ( )

4. Germinal Stage (Fertilization to 2 Weeks) • ________ divides, becomes more complex, and is implanted in the wall of the uterus • Within 36 hours rapid cell division and duplication (___________) begins • Continues until the original single cell has developed into 800 billion or more cells

5. Embryonic Stage (2 to 8 weeks) • Characterized by the ________ growth and development of major body systems and organs – respiratory, digestive, and nervous • __________ more likely than females to be spontaneously aborted or stillborn (125 males to 100 females/______ males to 100 females)

6. Three Week Embryo • Specialization of cells is under way and is extremely rapid

7. 8 Week Embryo • You can see eyes, a jaw, arms and legs • the brain and nervous system are developing rapidly • the heart has been beating for nearly a month

8. Fetal Stage (8 Weeks to Birth) • Fetus grows rapidly to about ______ times its previous length, and organs and body systems become more complex • _____________________ • high-frequency sound waves to detect the outline of a fetus and its movements • Breathe, kick, turn, squint, swallow, make fists, hiccup and suck their thumbs

9. Fetal Stage • Begins when ____________turns to bone and ends at birth • increase in size is remarkable (less than an ounce to an average of 7 to 8 pounds) • finishing touches are placed on the systems essential to human life • ____________________ is 7 months (28 w)

10. Prenatal Development: Environmental Influences • Maternal Factors: • Everything that affects mom’s well-being, from _______to moods, may affect her unborn child’s growth • Vulnerability to abnormality may depend on a gene either in the fetus or in the mother • ___________________ during fetal growth may have long-range effects • Critical importance of _________ acid, or folate (a B-vitamin)

11. Prenatal Development: Environmental Influences • Maternal Factors: • __________ also increases the risk of other complications of pregnancy, including miscarriage, stillbirth, and neonatal death • Pregnant women can exercise moderately, not pushing themselves and not raising their heart rate above 150, and, as with any exercise, to taper off at the end of each session rather than stop abruptly

12. Prenatal Development: Environmental Influences • Maternal Factors: a) ________ Intake (alcohol, nicotine, marijuana, opiates, cocaine) b) _________________________(HIV,syphilis, genital herpes, rubella) c) __________________ d) Outside Environmental Hazards

13. a) Drug Intake: Alcohol • ______________________ Syndrome (FAS) • Combination of mental, motor and developmental abnormalities affecting the offspring of some mothers who drink during pregnancy • _______________________________ (FAE) • NO SAFE AMOUNT – even a drinking binge of 4 hours or more can do tremendous damage to the developing brain

14. a) Drug Intake: Nicotine • ______of female smokers continue throughout pregnancy • Can cause miscarriage, neonatal death, low birth weight, and need for intensive care • Shorter, lighter, and poorer respiratory functioning • Increase risk of ________ in child • Second-hand smoking – same effects prenatally and postnatally as well increased risk on SIDS and inner ear infections in infancy

15. Long-term effects of alcohol and nicotine • When the children reach age: poor attention span, hyperactivity, anxiety, learning and behaviour problems, poor IQ scores, ___________________ problems

16. a) Drug Intake: Marijuana, Opiates, and Cocaine • _____________ -Neurological disturbances (tremors, startles), higher rates of low birth weight, cancer causing mutations • ____________- likely to bear premature, addicted babies who will be addicted to the same drugs and suffer the effects until at least age 6, infants often are restless, irritable, have tremors, convulsions, fevers • ___________ – higher risk prematurity, LBW, not as alert, less responsive, irritable, less able to regulate sleep, neurological stress

17. b) Sexually Transmitted Diseases • ______________– undermines the functioning of the immune system • Can cross over to the fetus’s bloodstream through the placenta • Can be transmitted through breast milk • Incidence of genital herpes has increased causing blindness, other abnormalities, or death • ____________- If contracted by the 11th week of pregnancy almost certain to cause deafness, heart defects (more common in non-industrialized countries)

18. c) Maternal Age • ______of all babies are born to women over the age of 30 • Older – more likely to have complications due to diabetes, high blood pressure, severe bleeding, greater risk of miscarriage and stillbirth, increase in operative deliveries (_____________, forceps) • Adolescents – premature, underweight , heightened risk of death, disability, or health problems

19. d) Outside Environmental Hazards • Chemicals, radiation, extremes of heat and humidity • ___________ levels of lead, heavy metals, nuclear radiation • Linked to higher rates of childhood _____________, lower measured intelligence, chromosomal malformations

20. 2. Paternal Factors • A man's exposure to lead, marijuana or tobacco smoke, large amounts of alcohol or radiation, DES, or certain pesticides may result in abnormal sperm • _______________ • _______________ • _______________

21. Since cocaine, marijuana, tobacco, and other substances can produce genetic abnormalities in a man's sperm, should men of childbearing age be forced to abstain from them? How could such a prohibition be enforced?