7. Teratogens

Question 1

Radioactivity

Answer 1

Chromosomal abnormalities, prenatal death and mental retardation

Question 2

Critical period

Answer 2

Vulnerable to toxin, viruses and genetic abnormalities
Embryonic: week 1-8
Fetal: week 9-birth
Postnatal development

Question 3

Cumulative risk

Answer 3

Effect may be worse if other risk factors are present (poor nutrition, lack of medical care, other teratogens)

Question 4

Thalidomide

Answer 4

Drug to prevent morning sickness during first trimester
Critical period for limb formation: babies born without long bones of their arms and legs (epidemic of phocomelia)
Drug still used today for leprosy and scleroderma (skin defects)

Question 5

Bisphenol A

Answer 5

Polycarbonate plastic (in baby bottles)
Estrogenic effects
BPA-alternatives are not always less toxic
BPA interferes with behavioral development (affects genital organ development, lower sperm quality, lower birth weight)
Brain mimics or blocks normal effect of estrogens
Estrogens are necessary for normal brain development

Question 6

Fetal Alcohol Syndrome

Answer 6

CNS problems
Low birth weight and height
Typical facial features
Fetal alcohol effects result from maternal alcohol abuse but not the full syndrome (FAE)
Birth defects last a lifetime
Alcohol penetrates placenta-fetus-embryo barrier

Question 7

Nicotine

Answer 7

Constricts blood vessels (reduces blood flow to uterus and causes placenta to grow abnormally, reduces transfer of nutrients to fetus)
Raises concentration of carbon monoxide (and decresed oxygen) in mother’s and fetus’ bloodstreams (likely to slow fetal growth and may damage CNS)

Question 8

Tabacco

Answer 8

Fetal and neonatal deaths: preterm births and lower birth weights: sudden infant death syndrome (SIDS): poorer language and cognitive development and 4 years

Question 9

Heroin and methadone

Answer 9

Deficient growth, SIDS, withdrawal symptoms, premature birth

Question 10

Rubella (rode hond)

Answer 10

Infection in 1st trimester: 20% of embryos will get rubella infection
Results in congenital rubella syndrome
Cardiac defects, deafness, some cases mental retardation
Eye anomalies
The earlier the greater malformations
Spontaneous abortion, still-born baby
Vaccine

Question 11

Mercury

Answer 11

Prenatal exposure leads to affects children’s mental development
Disorders of CNS, small heads (minimata disease)