Week 4: Principles of teratology

Question 1

Principles of teratology

Answer 1

• critical period: usually 3-8 weeks of pregnancy. However, important for some agents, but not others
• depends on dose response relationship, bioavailability
• some degree of genetic predisposition, because not all exposed fetuses affected

Question 2

FDA drug use in pregnancy categories

Answer 2

• information sparse and inaccurate
• some drugs such as OCPs are X even though there is no evidence of human fetal risk
• many drugs not studied or not studied in humans

Question 3

Effect of alcohol on fetus

Answer 3

• prenatal and postnatal growth deficiency, irritability, hyperactivity, fine motor dysfunction, poor attention span
• microcephaly, short palpebral fissures, maxillary hypoplasia, long and smooth philtrum, thin upper lip
• cleft lip
• heart and kidney malformations
• intellectual disability, cerebral palsy

Question 4

effect of anticonvulsants on fetus: hydantoin, valproate, carbamazepine

Answer 4

• increased risk of spina bifida

- valproate: decreased IQ, disrupts folate metabolism, autism

Question 5

Effects of antidepressants on fetus

Answer 5

• only paroxetine (paxil) associated with teratogenic effect- cardiac defects
• also increased risk for pulmonary HTN

Question 6

Effect of cigarette smoking on fetus

Answer 6

• pregnancy loss
• low birth weight
• double risk for cleft palate. also gastroschisis
• increased risk for asthma
• risk for neurodev. problems

Question 7

effect of maternal insulin dependent diabetes on fetus

Answer 7

-heart defects: cardiomyopathy
-spina bifida, other neural tube defects
-limb reduction
-microcephaly
-urinary tract anomalies
-Maternal hyperglycemia causes increased metabolic overload
directed at mitochondria, leading to more ROS and
oxidative stress
-Impaired embryonic gene expression due to oxidative stress and then disturbed organogenesis may be mechanism to explain diabetic embryopathy