TERATOGEN
Objectives
You will be able to… Analyze environmental factors that affect fetal
development Determine ways to prevent some birth defects Create an informational advertisement to new
parents about common teratogens.
Teratogen:
Anything that increases the risk of prenatal abnormalities
Behavioral Teratogen: causes no physical defect, but
affects the brain,making the child hyperactive,
antisocial, orlearning-disabled.
Types of Teratogens
Prescription Drugs Pollutants Social/Illegal Drugs Disease/Viruses Radiation/Chemical Warfare Malnutrition Stress
Determining the extent of damage to the fetus depends on…….
1. Critical Time of Exposure If exposure occurs during the embryonic period:
will result in major impairments and malformations
Exposure during the fetal period: results in growth impairments of the brain,
eyes and genitals
2. Duration of Exposure
The length of time the mother is exposed to the
teratogen greatly influences the effects on the fetus.
Example:
The mother visits a friend’s house where people
smoke inside. She only stays over for a few hours.
The mother lives in a house where people smoke inside. She is exposed everyday.
3. Genetic Susceptibility- Genes influence the effects of a teratogen:
Example:
The way the mother metabolizes a certain drug will determine
how much the fetus will be exposed to it.
THINK, WRITE, PAIR, SHAREThink of some examples of TIME (how many weeks
gestation) and DURATION (how long was the
mother exposed to the toxins) What kinds of toxins could someone be
exposed to over a long period of time (When)? How long? Which areas of the body would be affected? Why?
What kinds of toxins might need only a little bit of time to cause damage? How long? Which areas? Why?
Thalidomide(prescription drug)
Was a prescription drug sold mainly during the late 1950’s early 1960’s, used to alleviate morning sickness.
Critical period for exposure is during organogenesis
Specificity of malformations is linked to time of exposure:
35-37 days- no ears39-41 days- no arms41-43 days- no uterus45-47 days- no tibia47-49 days triphalangeal thumbshttp://
www.youtube.com/watch?v=O8ucuLpECNw
Industrial Chemicals
Cleansers, varnishes, lacquers, resins, leads, pesticides, herbicides (agent orange) and mercury (Minimata Disease)
http://fyiliving.com/videos/fish-to-avoid-during-pregnancy/
Illegal Drugs, Alcohol and Tobacco
Low birth weight Born addicted to drugs Withdrawal symptoms
Fetal Alcohol syndrome
Behavioral problems/impulse control
Maternal Disease Rubella Herpes simplex, AIDS Chickenpox If the mother has these diseases-
can cause serious
malformations, mental
retardation and miscarriage or
Infant mortality.
Other Maternal Influences Malnutrition (lack of necessary
vitamins, minerals and proteins)FOLIC ACID- Is a B-vitamin that helps
create new cells.
Spina Bifida http://
www.qualityhealth.com/pregnancy-videos/preventing-spina-bifida-newborns-folic-acid
Stress/Anxiety Altered Metabolism (Diabetes
mellitus)
ACTIVITY Go to www.otispregnancy.org Click on “FACTSHEETS” in the right toolbar Choose 1 factsheet to research Make an informative flyer including:
Definition- 5pts Common reason a woman would be exposed to this
potential teratogen- 5pts In your own words: Can this potential teratogen cause
birth defects?- 5pts Conclusion: What would you suggest if someone asked
you if exposure to this potential teratogen was ok? – 5pts
20 POINTS TOTAL!
References http://a.abcnews.com/Health/popup?id=4610286&contentIndex=1&page=
2&start=false http://www.kianh.org.uk/agentorange.htm http://hidhist.wordpress.com/category/gulf-war-syndrome/ http://www.who.int/violence_injury_prevention/violence/world_report/fact
sheets/ft_child.pdf http://www.who.int/ceh/risks/en/ http://carolguze.com/text/442-13-teratogens.shtml http://www.pixelpress.org/chernobyl/index.html http://books.elsevier.com/companions/0240804155/crack/crack1.htm http://www.whale.to/a/gulf32.html http://embryology.med.unsw.edu.au/Defect/rubella.htm (awesome
website!!) Slater, A. & Lewis, M. (2007). Introduction to infant development. New
York: Oxford University Press.
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