Fetal Toxicology (Segar) Flashcards
a physical defect present in the fetus or infant is called a what?
malformation
extrinsic mechanical force on otherwise normal tissue may lead to a what?
deformation
____ is a malformation that results from failure to close the anterior neural tube prior to 26 days
anencephaly
sequelae from this condition caused by lack of amniotic fluid (oligohydramnios) include characteristic facies, contractures, and pulmonary hypoplasia
potter syndrome
an extrinsic insult which destroys normal tissue (ie, amniotic bands) is known as what?
disruption
a lack of normal organization of cells into tissue (ie, multicystic kidney) is known as what?
dysplasia
substances that may cause structural and/or dose dependent, functional abnormalities are known as what?
teratogens
Which of the following statements about teratogens is INCORRECT?
A. Teratogens may include recreational drugs but not medicinal drugs.
B. The extent of damage a teratogen may cause depends on getstational timing, intentisty/duration of an exposure, and individual susceptibility.
C. The embryo is most susceptible to teratogenic agents during period of rapid differentiation.
D. Teratogenicity depends on the ability of the agent to cross the placenta.
E. Teratogens include chemical or infectious agents that may alter the fetal morphology or subsequent function
A is incorrect. Teratogens may include recreational or medicinal drugs, as well as behavior or environmental exposures.
what window of gestation is a teratogen most likely to produce major structural abnormalities?
week 3-8 of gestation (embryonic stage)
teratogenic exposure during this stage of development will affect the growth of the fetus and the function of organs
(fetal stage)
The ______ rate of many drugs increases during late pregnancy due to increases in both hepatic and renal elimination processes (e.g., digoxin, phenytoin), while in some cases the rate decreases (e.g., theophylline).
clearance
this condition is the leading known cause of preventable intellectural disabilities, and is characterized by a thin upper lip, small eye openings, flat midface, and retardation of mental development and phyiscal growth
fetal alcohol syndrome (FAS)
condition caused by anti-epileptic phenytoin (10%-30% of cases) that may result in IUGR, microcephaly, mental retardation, distal phalangeal hypoplasia and specific facial features like cleft lip and hypertolerism
fetal hydantoin syndrome
syndrome that results from the teratogenic effect of induced hypervitaminosis A during pre- and embryonic development, which alters HOX signalling and results in craniofacial, cardiovascular, thymic and CNS dysmorphisms
fetal retinoid syndrome
synthetic nonsteroidal estrogen prescribed for pregnancy in the 40s-70s that caused increased risk of breast cancer in mother and pregnancy complications, infertility, reproductive tract dysmorphisms, and clear cell adenocarcinmoa in offspring
DES
