Chapter 3: Prenatal
Development and Birth
Teratogens: Hazardous to the
Baby’s Health
By Kati Tumaneng
(for Drs. Cook & Cook)
Teratogens: Hazardous to the
Baby’s Health
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Most defects occur from unknown causes.
1/3 related to environmental factors during
prenatal development.
Fetus buffered but not fully protected.
Teratogen – Any substance or condition that
might disrupt embryonic development and
cause birth defects.
More info on birth defects from March of Dimes: www.modimes.org/
Alcohol
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19% pregnant women drink alcohol during
pregnancy.
Can cause physical deformities, growth
retardation, damage to the central nervous
system, and miscarriage and fetal death.
Children at greater risk for being impulsive,
easily distracted, and hyperactive; having
retarded brain growth and lowered IQ.
Leading non-genetic cause of mental
retardation in US.
Alcohol
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Fetal Alcohol Syndrome (FAS) – Syndrome of birth
defects cause by prenatal exposure to alcohol.
Includes growth deficiencies, head and facial
malformations, and central nervous system
dysfunction. Fully preventable.
Fetal Alcohol Effects – Individual or multiple birth
defects caused by prenatal exposure to alcohol.
Lowered IQ, hyperactivity, growth deficiencies, head
and facial malformations, and central nervous system
dysfunction.
There is no safe level of alcohol consumption.
Alcohol
Child with FAS
Cocaine
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1 in every 100 pregnant women use cocaine; may be
underreported.
Fetal exposure retards growth, can cause preterm
birth, and can cause malformation in baby’s brain,
intestines, and genital-urinary tract; hemorrhage,
lesions, and swelling in brain.
Increased irritability, muscle tremors, rigidity,
decreased spontaneous movement; impaired sensory
function, decreased visual attention, and trouble
regulating their own state of arousal.
Cocaine
Cigarette Smoking
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12 percent of pregnant women smoke.
450 different harmful chemicals in cigarette
smoke.
Mother and baby gain less weight; baby more
likely to be premature and have health
complication.
More likely to be hyperactive, have short
attention span, and score lower in reading,
spelling, and math.
Increase risk for spontaneous abortions,
stillbirths, and neonatal deaths.
Quit Smoking: http://www.hc-sc.gc.ca/hl-vs/tobac-tabac/index_e.html
Maternal Diseases
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Infectious diseases carried by mother, may
endanger the fetus.
May cause birth defects or death.
Herpes Simplex Virus
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May be transmitted at birth if mother is showing
symptoms.
Premature, microcephaly, eye disorders, and
mental retardation.
Cytomegalovirus dangerous, especially during
weeks 2-8.
STD’s: http://www.niaid.nih.gov/dmid/stds/
Maternal Diseases
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Syphilis
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1 in every 10,000 babies born with Syphilis.
Birth defects include deafness, malformations of
teeth and bones, facial deformities, excess fluid in
the brain, and mental retardation.
Prompt treatment of mother may protect baby.
HIV/AIDS
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Effects not yet clear but may include growth
retardation and head and facial deformities.
Baby usually contracts at or near delivery;
infection risk increases with breast-feeding.
Maternal Age
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900,000 teenagers become pregnant in US
each year; nearly ¼ of all births.
Risk of low birth weight is highest in mothers
under 15 and over 45.
Young mothers not socially and cognitively
mature enough to cope with stress in early
pregnancy.
Factors associated with teenage pregnancy:
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Low income, poor education, social isolation, drug
and alcohol use, lack of early prenatal care.
Maternal Age
Maternal Age
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Women in late 30’s and into 40’s have
greater risk of prematurity, fetal death,
and complications during birth.
Increased risk of Down Syndrome.
Even with increased risk, majority of
pregnancies are normal.
Critical Periods
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Segments of time when structures are first.
forming and are most vulnerable to damage.
Developing organism is at greatest risk for
abnormalities during the Embryonic stage
(weeks 3-8).
Women not often sure of pregnancy before
8th week.
Lifestyle changes then may be too late.
Critical Periods
What about Fathers?
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When toxic substances affect sperm cells, the
damaged sperm usually do not survive
journey to the egg.
Cocaine may disrupt development of zygote.
Most birth defects result from mother’s
exposure to toxins.
Men should consider how they contribute to
prenatal hazards.
Healthy pregnancy is the responsibility of
both men and women.
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Child on Slide 5: from Cook, J. L., & Cook, G. (2005). Child
development: Principles and perspectives (1st ed.) (p. 97).
Boston: Allyn and Bacon.
Infant on Slide 7: from Cook, J. L., & Cook, G. (2005). Child
development: Principles and perspectives (1st ed.) (p. 98).
Boston: Allyn and Bacon.
Chart on Slide 12: from Cook, J. L., & Cook, G. (2005). Child
development: Principles and perspectives (1st ed.) (p. 101).
Boston: Allyn and Bacon.
Chart on Slide 15: from Cook, J. L., & Cook, G. (2005). Child
development: Principles and perspectives (1st ed.) (p. 103).
Boston: Allyn and Bacon.
All images retrieved from Microsoft PowerPoint Clip Art.