Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Pregnancy and Prenatal Development: Lecture Week 4

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 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?

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Prenatal Development: Three Stages 1. Germinal Stage ( ) 2. Embryonic Stage ( ) 3. Fetal Stage ( )

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 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

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 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)

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Three Week Embryo Specialization of cells is under way and is extremely rapid

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 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

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 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

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 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)

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 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)

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 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

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Prenatal Development: Environmental Influences 1. Maternal Factors: a) ________ Intake (alcohol, nicotine, marijuana, opiates, cocaine) b) _________________________(HIV,syphilis, genital herpes, rubella) c) __________________ d) Outside Environmental Hazards

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 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

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 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

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 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

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 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

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 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 11 th week of pregnancy almost certain to cause deafness, heart defects (more common in non-industrialized countries)

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 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

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 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

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 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 _______________

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display 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?