INDEX
 What is a Teratogen? - 2
 Vulnerable Periods in Prenatal Development - 3
 Examples of Infectious Diseases - 4
 HIV and AIDS - 5
 Transmission of Infectious Diseases - 6
 Examples of Recreational and Prescription Drugs - 7
 Reports of Use of Teratogens During Pregnancy - 8
 Classification of Medication - 9
 Examples of Environmental Factors – 10-12
 Therapy for the Emotional and Physical Effects of Teratogens - 13
 Works Cited – 14
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What is a Teratogen?
o A teratogen is any environmental agent that harms the embryo or fetus
o Teratogens can cause miscarriages, birth defects, and other difficulties during pregnancy
o The two types of teratogens are infectious diseases and various chemical substances
o Examples of infectious diseases that can affect a developing fetus are syphilis, toxoplasmosis,
chickenpox, genital herpes, etc.
o Social drugs and prescription medications can also act as teratogens
o Exposure to some chemicals such as paints or pesticides in the mother’s environment act as teratogens
as well
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Vulnerable Periods in Prenatal Development
o Prenatal development is the process when a human fetus gestates throughout pregnancy
o Prenatal development occurs from fertilization until birth
o After fertilization the embryonic period starts
o During this period, there is the greatest risk of being affected by teratogens
o The central nervous system, heart, arms, legs are less susceptible to teratogens but can still be affected
o At the start of about 9 weeks, the fetal period begins
o The central nervous system, ears, eyes, teeth, palate, and external genitalia are less susceptible to teratogens but they can
still potentially end up being affected by them
o The baby is full term at about 38 weeks
No defects
temporary or reversible defects
continuing effects
2%
3%
95%
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Examples of Infectious Diseases
o The main diseases that act as teratogens and cause major birth defects are STORCH diseases
o Syphilis: can cause blindness, mental retardation, and deafness. 25% infected die soon after birth,
25% die during the second trimester
o Toxoplasmosis: can cause spontaneous abortion, premature delivers, cerebral palsy, anemia, etc.
o Other Infections: ordinary infections like H1N1 can lead to a pregnant woman’s death
o Rubella: can result in cataracts, mental retardation, congenital heart disease, etc.
o Cytomegalovirus: can cause long-term hearing or vision loss and learning disabilities. 90% show
no symptoms at birth
o Herpes: one third of babies who are infected die, one fourth develop brain damage
Infant infected with Rubella,
or German Measles rash
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HIV and AIDS
o Human Immunodeficiency Virus (HIV)/Acquired Immune Deficiency Syndrome (AIDS) are diseases
that can be passed from mother to baby during pregnancy.
o HIV is present in the bloodstream and genital secretions, can be transmitted when blood or
secretions are exposed to mucous membranes or breaks in skin.
o Only 1 in 4 babies born to mothers infected with HIV develop AIDS.
o Treatment with zidovudine ZDV or other drugs early in the pregnancy may help to prevent the
transmission of the virus.
o Estimates are that an infected mother transmits HIV from 30%-50% of the time so 50%-70% of
fetuses remain unaffected.
o When the virus is transmitted, condition called AIDS embryopathy can develop which causes
growth retardation, small head size, flat nose, and widespread, upward-slanted eyes, etc. .
o AIDS has a shorter incubation period in fetuses than in adults, so symptoms may appear as early
as 6 months and after birth and include weight loss, fever, diarrhea, and chronic infections.
o Once symptoms appear, babies rarely survive more than 5 to 8 months.
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Transmission of Infectious Diseases
o Some diseases that the mother may have can be passed through vertical transmission
o Vertical transmission is also known as prenatal transmission
o Vertical transmission is the passing of a pathogen from the mother to child either directly before or
after birth
o Vertical transmission can arise in the placenta, through the breast milk, and through direct contact
with the infection
o HIV is a common disease that is passed from mother through vertical transmission
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Examples of Recreational and Prescription Drugs
Chemical
Substances
Time of Risk
During
Pregnancy
Alcohol
Throughout
pregnancy
Aspirin
Last month, at
birth
Possible Effects
Alcohol: Fetal alcohol syndrome (FAS), growth retardation,
cognitive deficits.
Aspirin: Bleeding problems
Cigarettes: Prematurity, lung problems
Cigarettes
After 20 weeks
DES: Cancer of female reproduction
DES
From 3 to 20
weeks
LSD: Isolated abnormalities
LSD
Before conception
Lead: Death, anemia, mental retardation
Lead
throughout
pregnancy
Marijuana
throughout
pregnancy
Marijuana: Unknown long term effects, early neurological
problems
Thalidomide
the first month
Cocaine
throughout
pregnancy
Thalidomide: Fetal death, physical and mental abnormalities
Cocaine: Spontaneous abortion, neurological problems
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Reports of Use of Teratogens During Pregnancy
continue to smoke cigarettes
drinking alcohol
using illict drugs
other
20%
13%
62%
5%
Reports during Pregnancy
(Arenson & Drake, 2007)
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Classification of Medication
A
Common drugs that have been taken by pregnant
B
Drugs that have been taken by only a limited number of
women without any proven risk of birth defect.

pregnant women. Data is lacking and they are
categorized based on data from animal studies.
B1
Drugs You Should Avoid During Pregnancy
Animal studies have not shown any increased risk.





B2
There do not seem to be any increased risk.
B3
animal studies show an increased risk, but it is not clear

if this risk applies to humans.

C
Drugs that may cause harm to the fetus without causing

D
Drugs that have caused or may cause birth defects;

however, the health benefit may outweigh the risk.



birth defects. These effects may be reversible.


X
Drugs that have a high risk of birth defects and should

ACE (angiotensin converting enzyme)
inhibitors
Angiotensin II antagonist
Isotretinoin (an acne drug)
Alcohol
Cocaine
High doses of vitamin A
Lithium
Male hormones
Some antibiotics
Some anticonvulsant medications
Some cancer-fighting medications
Some drugs that treat certain rheumatic
conditions
Some thyroid medications
Thalidomide
The blood-thinning drug warfarin
The hormone diethylstilbestrol (DES).
not be used during pregnancy.
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Examples of Environmental Factors
Exposure to methyl mercury during pregnancy can have many affect on fetal nervous system development. In
recent years fish and seafood has began to be the primary sources of mercury poisoning. Certain types of fish
and other seafood contain high levels of mercury, which can pose a risk of teratogenic effects on an unborn
child. The longer a fish lives the more mercury accumulates in its tissues.
Consumption of the following fish should also be limited:
1
2
3
4
5
Halibut (one meal per month)
Orange Roughy (one meal per month)
Salmon and shellfish (two to three meals per week maximum)
Canned tuna; albacore has more (less than one can of six-ounce tuna per week)
Cod, Pollock, Haddock (one meal per week)
Arsenic and cadmium are both metals, which can pose a threat to the developing fetus. Evidence suggests that
women living near metal smelters, agricultural areas where arsenic-containing fertilizers were once used, or
hazardous waste sites or incinerators are at greater risk for miscarriage and stillbirth.
The best ways to protect yourself from the birth defect risks posed by arsenic and cadmium include:
1
2
3
4
Have your water tested for arsenic or drink only well-filtered water
Limit contact with the soil
Avoid wood dust from construction projects (as pressure-treated wood may contain arsenic)
Workers in the metal, herbicide, or semiconductor manufacturing industries should avoid bringing metal home on
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Environmental Factors Continued
Cadmium is present in semiconductor manufacturing, welding, soldering, ceramics, and painting industries and
applications. Pregnant women may wish to have the following products removed from the home to avoid
cadmium exposure or cadmium poisoning:
1
2
3
4
Fungicides containing cadmium chloride
Ceramic and glass glazes
Certain fabric dyes
Some fertilizers
Pesticide exposure should be avoided whenever possible during pregnancy. Pesticides may contain numerous
chemicals used to eradicate unwanted insect and flora.
Experts recommend the following precautions regarding insecticides:
1
2
3
4
5
6
7
8
Have pesticide sprayed in absence of pregnant women
Remove all cookware and eating utensils from the environment before application
Close all windows and turn off air conditioning when pesticides are used outside the home
Women should avoid treated areas for at least eight hours following application
The area must be adequately ventilated during the hours after application
Wear rubber gloves when gardening
Products containing high concentrations of DEET (insect repellants) should be avoided during pregnancy
Lice treatment Kwell is to be avoided during pregnancy, since it has been associated with central nervous system toxicity.
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Environmental Factors Continued
The following pesticides are known to disrupt the endocrine system and may increase the risk of birth defects:
alachlor, amitrole, atrazine, carbaryl, chlordane, dieldrin, DDT, endosulfan, oxycholordane, metribuzin, nitrofen,
fungicides, benomyl, metiram-complex, hexachlorobenzene, mancozeb, maneb, tributyl tin, zineb, zirem, and
many more.
Organic solvents are used commercially and at home to dissolve other substances. These solvents can include
alcohols, paint thinners, lacquers, nail polish removers, silk screening inks, paints, degreasers, and varnish
removers. Exposure to organic solvents during the first trimester of pregnancy
can increase the risk of birth defects like spina bifida, heart defects, clubfoot, and
Right: infant with clubfoot
deafness.
Left: infant with spina bifida
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Therapy for the Emotional and
Physical Effects of Teratogens
Family & Children’s Center
315 West Jefferson Street South Bend, Indiana
(574)232-2255
Neil Gilbert Counseling & Healing
914 Lincoln Way West South Bend, Indiana
(574)287-0391
Women’s Care Center
1635 North Ironwood Drive South Bend, Indiana
(574)273-8986
For poison emergency in the U.S. call 1-800-222-1222
Poison Control Center
Indianapolis, Indiana
(317)962-2323
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Works Cited
Better Health Channel. "Birth Defects - Drugs and Medications." Home. State Government of Victoria, 8 Dec.
2011. Web. 29 Mar. 2012. <www.betterhealth.vic .gov.au/bhcv2/bhcarticles. nsf/pages/Birth_defects_
and _ drugs?open>.
Fiore, Lisa B. Lifesmart. New York: McGraw-Hill Higher Education, 2010. Print.
"MedicineNet.com." Medterms. Web. 28 Mar. 2012. <www.medterms .com/script/ main/art.asp ?
articlek ey =79 82>.
Oshman, and Mirisola. "Birth Defects and Enviromental Hazards." Birth Defects, E nvironmental
Hazards, Practice Areas, New York Medical Malpractice Attorneys, Toxic Tort. Oshman & Mirisola, LLP,
2012. Web. 28 Mar. 2012.<www.oshmanlaw.com/toxic_tort/ birth_ defects _ envi ron men ta l_
causes.html>.
"Teratogens." Illinois Teratogen Information Service. Web. 24 Mar. 2012. <www.fetal-expos ure. org/
teratogen.aspx>.
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