Teratology Flashcards
What is considered a minor anomaly in teratology?
Are not themselves detrimental to health
(i. e. small ears, pigment spots)
- occur in ~15% of newborns
Minor anomalies serve as clues for diagnosing more serious defects
What are causes of birth defects?
- Genetics
- Environmental Teratogens
- -> Infectious agents
- -> physical agents
- -> chemicals agents
- -> hormones
What are the two groups of anomalies?
- Syndrome
- Group of anomalies that occur together from a specific common cause
- cause has been determined
- risk of recurrence is known - Association
- non-random appearance of anomalies
- cause has not been determined
What are the principles of teratology?
- Genotype of conceptus determines susceptibility of teratogenesis
- Susceptibility to teratogens varies depending on development age of exposure
- Dose and duration of exposure to teratogen determines manifestations of abnormal development
- Teratogens act in specific ways on developing cells/tissues to initiate abnormal development
- Manifestations of abnormal development are:
Death
Malformation
Growth Retardation
Functional Disorders
When is the conceptus most susceptible to teratogens?
During the period of embryogenesis
–> may be one or more stages of susceptibility
- no stage is completely safe
What infectious agents are considered teratogens?
TORCH
Toxoplasma
Rubella
Cytomegalovirus
HSV
Elevated body temperature - infections with fever can cause birth defects
What teratogen is concurrent with the following congenital malformations:
Cataracts
glaucoma
heart defects
deafness
tooth abnormalities
Rubella virus
What teratogen is concurrent with the following congenital malformations:
Often fatal
If not, includes:
microcephaly
blindness
mental retardation
Cytomegalovirus
What teratogen is concurrent with the following congenital malformations:
Micropthalmia
microcephaly
retinal dysplasia
HSV
What are the key features of Congenital Rubella Syndrome (CRS)?
- Replication of virus in throat for weeks
- high levels of virus present
- viral infection of the placenta
- All cells in fetus infected after maternal viral infection
- Confirmed rubella during 1st trimesster
What teratogen is concurrent with the following congenital malformations:
Anencephaly
Spina bifida
mental retardation
facial defects
cardiac abnormalities
limb defects
Hyperthermia
What teratogen is concurrent with the following congenital malformations:
Microcephaly
Spina Bifida
Cleft palate
limb defects
X-rays
What teratogen is concurrent with the following congenital malformations:
Limb defects - loss of long bones
heart malformations
Thalidomide
What teratogen is concurrent with the following congenital malformations:
Cleft lip and palate
heart defects
Amphetamines
What teratogen is concurrent with the following congenital malformations:
Growth retardation
microcephaly
addiction
Cocaine
What teratogen is concurrent with the following congenital malformations:
Depressed nasal bridge
Short nose
Flat midface
Indistinct philtrum
Thin upper lip
heart defects
metal retardation
Alcohol
What does FDA category A for use in pregnancy mean?
Example?
No risk shown in controlled human studies
Example: Prenatal vitamins
What does FDA category B for use in pregnancy mean?
Example?
Animal studies show no risk and with no risk in controlled human studies
OR
Animal studies show increased risk but controlled human studies show no risk
Example: Penicillin or Acetominophen
What does FDA category C for use in pregnancy mean?
Example?
Animal studies show incrased risk and no controlled human studies
OR
No animal or human studies
Example: nifedipine/sumatriptan
What does FDA category D for use in pregnancy mean?
Example?
Proven risk in humans
Benefits might outweigh risks
Example: Valproic Acid, Gentamicin
What does FDA category X for use in pregnancy mean?
Example?
Proven risk in humans, animals, or both
Risk outweight benifits
Example: Isotretinoin/Misoprostol/Warfarin (use heparin instead)
What disease causes caudal regression?
Diabetes
What drug inhibits abortion of an already malformed fetus?
Progestins
What drug inhibits the formation of long bones?
Thalidomide
20-30% of fetuses between the 27th and 40th day after conception
2-3x increaed risk for NTD due to impared folate metabolism
