Teratogens Flashcards
fetal hydantoin syndrome: is related to a ___ defect in the fetus
metabolic
when does the embryonic period end and the fetus period begins
at the end of the 10th completed week after menstration
period of greatest sensitivty of embryo to teratogens
3-8 weeks
FDA classification of risk
- studies in humans and animals
- demonstrate fetal abnormalities
- evidence of fetal risk
- risk of drug clearly outweighs any benifit
- dugs contraindicated in pregnancy or those who may become pregnant
Category X
FDA classification of risk
- positive evidence of human fetal risk
- benifits for use during pregnancy may be acceptable despite the risk
- drugs needed for life threatening situation
- other safer drug not available or ineffective
Category D
FDA classification of risk
- animal reproductive studies
- have demonstrated risk to fetus
- and there are no controlled studies in women
- or studies in women and animals are not available
Category C
FDA classification of risk
- animal reproductive studies
- have not demonstrated fetal risk
- no controlled studies in pregnanct woman
- or animal studies show adverse effect
- that was not confirmed in RCT of pregnant women
Category B
FDA classification of risk
- controlled studies in women
- fail to demonstrate risk to fetus in first trimester
- possibility of fetal harm seems remote
- category with fewest drugs
Category A
possible effects of ionizing radiation on fetus (4)
- growth retardation
- microcephaly
- eye defects
- possible risk of childhood leukemia with exposure of > 2rad during 3rd trimester
Embryonic abnormality associated with maternal hyperthermia at what stage of development?
neural tube defects
2-3 week embryo
maternal fever > 40 degree > 48 hours
maternal metabolic condition associated with caudal regression sirenomelia
Maternal diabetes
poorly controlled
low birth weight,
cutaneous scars,
papular lesions,
localized absence of skin on a limb,
hypoplasia of one or more limbs, malformed digits along with various ocular and central nervous system (CNS) abnormalities
Fetal varicella syndrome (FVS) is a rare complication of maternal varicella infection occurring in <2% of the babies born to women infected with varicella between 7 and 28 weeks of pregnancy
https://obgyn.onlinelibrary.wiley.com/doi/full/10.1002/pd.3843
growth delay
intellectual disability
hypoplastic distal phalanges and nails
cleft lip and palate
wide anterior fontanelle, metopic ridging, hypertelorism, broud flat nasal bridge
hirsutism
Fetal hydantoin syndrome
(Dilantin)
fetuses with deficiency of this enzyme develope fetal anticonvulasant syndrome
homozygous deficiency in dilantin epoxide hydrolase
can be diagnosed through parental carrier status
what is the specific congenital abnormality concern with valproic acid
neural tube defects
nasal hypoplasia and depressed nasal bridge
stipling of uncalcified epiphyses
nail/fingertip hypoplasia
low birth weight
mental retardation
Fetal warfarin exposure
abnormalities of the 1st and 2nd phalageal arch surrounding the 1st pharygeal cleft
35% risk for embropathy if used >2 weeks post conception
Retinoic acid Embryopathy
Isotretinoin (Accutane ) exposure
also associated with microtia, micrognathia, hypertelorism
conotruncal cardiac defects
hydrocephalus and developmental delay
fetal renal compromise: renal tubular dysgenesis
oligohydraminios
anuria
renal failure
fetal hypocalvaria
ACE inhibitors
likley karyotype of an ovarian teratoma?
46, XX, digynous
likley karyotype for a complete hydatidiform mole
46, XX or 47 XY diandrous
likley karyotype of the picture seen
complete hydatidiform mole
46, XX of 46 XY diandrous
first trimester screening
low hCG
low PAPP-A
small placenta
abnormal fetus
triplody
partial mole
formed by single sperm followed by duplication
69, XXX
69, XXY
first trimester screening
very high hCG
high PAPP-A
hydropic placenta and IUGR fetus
or gestational sac
triploidy
partial mole
formed by two sperms and 1 egg
69, XXX
69, XXY
congenital anomalies affect _____% of newborns
3-5%
