03 prenatal development

7/30/2019 03 Prenatal Development

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Prenatal Development

ß Dennis Karpowitz

ß Psychology 333

ß Child Psychology

Chris and Kim on Conception Island



Female Reproductive Organs



Conception

ß Every 28 days, an ovum, lasts 24 hours

ß Millions of sperm, viable for up to 6 days

ßConception in the fallopian tubeß Tubal pregnancy

ß Conceptions most likely:

on day of ovulationor the two days preceding ovulation



Conception



The Period of the Zygote or the

Germinal Stage

ß First Two weeks following conception

ß From fallopian tubes to attachment tothe uterine wall

ß Blastocyst, 60-70 cells, 4th day

ß Embryonic disk (organism)ßOuter Ring (umbilical cord & placenta)

ß Implantation between days 7 & 9



Zygote Period Continued

ß Amnion Membrane, amniotic fluid

ß Yolk sack produces blood cells

ß Chorion Membrane

ß Placenta - Food, oxygen, waste

ß Umbilical cord

ß 30% of zygotes do NOT survive



The Period of the Embryo

ß From 2nd week through 2nd month

ß Very rapid prenatal development

ß Embryonic disk folds into three layers

ß Ectoderm - Nervous system (fast develop.) & skin

ßMesoderm - skeleton, muscles, circulation

ß Endoderm - Digestion, lungs, urinary tract

5.5 Weeks 9 Weeks



Embryonic Period Cont.

ß Many body parts develop the 2nd monthß Fingers, toes, facial features, nervous system cells

fire, teeth buds have formed

ß Embryo’s posture becomes upright ß The embryo can move

ß The embryo responds to touch (mouth & feet)



11 Week Fetus



The Period of the Fetus

ß Growth and finishing

ß Third month

ßOrgans, muscles & nervous system

organize and connect

ß External genitals – visible with ultrasound

ß End of first trimester



Second Trimester

ß 13-24 weeks - first movement felt

ß Vernix covers fetus, prevents chapping

ßLanugo hold vernix to skin

ß Trillions of brain neurons produced

ß Stimulated by sound and light



Third Trimester

ßAge of viability - 22 to 26 weeks

ß Cerebral cortex enlarges

ßResponsive to external stimulation

ß Fat layer develops for temp. reg.ß Moves to the upside-down position

ß Fetus moves less



Teratogens

ß Environmental influences or agents that can

damage the developing organism



Influence of Teratogens

ß Larger doses, over time, more negative

ßGenetics can help or hinder teratogens

ß Several negative factors increase impact

ß Sensitive periods especially important

ß Embryonic period most susceptible

ß Physical and psychological effects



Drugs

ß Thalidomide –

sedative - 1960’s

ß Aspirin - low birth weight, infant death

Poor motor develop., lower IQ

ß Heavy caffeine use - miscarriage

Premature births, irritability



Illegal Drugs

ß Cocaine, heroin, methadone

ß Prematurity, low birth weight

ß Physical defects, breathing problems,

ßDrug addiction & death

ß Cocaine - lasting difficulties

ßGenital, urinary tract, kidney, heart deformities

ßBrain seizures



Crack babies

ß Lowest birth weight

ß Central nervous system damage

ßFathers on cocaine may pass it on

ß Multiple harmful effects of more than one

drug



Tobacco use

ß Low birth weight and premature births

ß Impaired breathing

ßMiscarriage & infant death

ß Placenta doesn’t work correctly

ß Greater concentration of carbon monoxide

ß Passive smoking also injurious



Alcohol

ß Fetal alcohol syndrome (FAS)ß Large amounts of alcohol, whole pregnancy

ßMental retardation

ß Slow physical growthß Facial abnormalities

ß Alcohol interferes with cell duplication

ß Especially neural cellsß Draws oxygen away from organism



Fetal Alcohol Syndrome



Hormones

ß Diethylstilbestrol (DES), 1945-70

ßVaginal cancer

ßMalformation of the uterus

ßMiscarriage, low birth weight

ß In males, genital abnormalities, cancer



Radiation

ß Hiroshima & Nagasaki

ßMiscarriage, slow physical growth

ßUnderdeveloped brains

ßMalformation of skeleton & eyes

ß X-Rays - avoid during pregnancy



Environmental Pollutants

ß 100,000 in common use

ß Mercury

ßMental retardation, speech problems

ßDifficulty chewing & swallowing

ßUncoordinated movements

ß Polychlorinated Biphenyl (PCB)

ß Lower birth weight, smaller heads

ß Poor memory, lower verbal IQ



Maternal Disease

ß Viruses - Most not harmful

ß Rubella

ßHeart defects, cataracts, deafness

ßGenital, urinary & intestinal problems

ß HIV & AIDS

ß 20-30% Mothers pass to infants

ß Fast growth in infants

ßMost survive 5 to 8 months



Maternal Disease Cont.

ß Herpes viruses

ßBabies infected during pregnancy

or at birth

ß Bacterial & Parasitic Diseases

ß Toxoplasmosis from meat or cats

ß 40% transmission

ß Eye & brain damage



Positive Health Activities

ß Moderate, low impact exercise

ß Healthy diet - vitamin supplements

ßMalnutrition causes problems

ßWIC Program

ß Low stress

ß Intense anxiety >> miscarriage, premature

birth, low birth weight, respiratory illness,

Cleft palate & Pyloric stenosis



Rh Factor

ß Mother Rh -, father Rh+, Child Rh+

ß Antibodies against foreign Rh protein

ßRhoGam within 72 hours



Prenatal Health Care

ß Every month of pregnancy visit MD

ß 2X/Month for the last two months



Watch For . . .

ß Diabetes complications

ß Toxemia

ß Get vaccinations before becoming pregnant



Prenatal Courses

ß Information: Birth & Parenting

ß Exercises

ßSupport

03 prenatal development

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