teratogens Flashcards
risk of major malformation in the general pop is
1-3 %
what are the causes of congenital malformations?
65% uknown
25% genetic
< 1 % drugs/chemical
when is the all or non period in embryology
time after ovulation before implantation 12 days
when are most morphological features formed?
by the first trimester
when does the placenta play a role as a barrier
after 5 weeks gestation -
hyperglycemia in first 8 weeks of pregnancy increases risk of
cardiac defects
neural tube
hyperglycemia inducing apoptosis
risks of uncontrolled DM on neonate
hypoglycemia after birth
severe maternal hypothyroidism can cause
decreased IQ
3 conditions where antibodies cross the placenta
1- lupus: can get congenital heart block
2- graves disease: fetal hyperthyroidism
3- IPT: fetal thrombocytopenia
Isotretinoin accutane can cause
miscarriage in 40%
malformations in 25%
- small ears
- cardiac and neurological problems
thalidomide malformations
- phocomelia - flipper like appendages
period of risk for fetal warfarin syndrome
6-9 weeks
nasal hypoplasia
IUGR?
Stippled epiphyses
when does the Neural tube close?
3-4 weeks - EARLY
-
Carbamazepine has an early side effect
just NTDs 1% risk - at 3-4 weeks
Lamotrigine
has no effects on malformations
Valproic acid
AVOID
-2% risk - possible cardiac anomalies, emerging concern about neurocognitic development
Phenytoin can case
craniofacial abnormalities
impaireed growth
fetal hydantoin syndrome
Risk is <10%
When are ACE inhibitors teratogenic?
second and third trimester
- cause oliguria, renal failure, contractures, thin scalp
lithium causes
Ebstein’s anomaly - insertion of the tricuspid valve is misplaced
risk < 1%
what can you give an 18 week pregnant woman who has a DVT
Heparic and LMWH
- cant cross the placenta
To treat asthma
bronchodilators are safe
inhaled steroids are safe
Systemic steroids can
increase risk of cleft-lip and palate by 2-fold
what is the amount of radiation that can cause miscarriage or malformations?
> 5-15 rads
fetal alcohol syndrome can cause a triad
growth retardation
dysmorphic facies
decreased IQ and behavioral abnormalities
how much alcohol to cause FAS
- 8 beers a day
2g/kg/day
how much folic acid
1-5 mg daily for 3 months prior to conception
when are drugs generally considered safe in infants
relative dose < 10%
