Teratogens Flashcards
teratogenic exposure at ___ stage results in major structural defects?
organogenesis stage
week 3-8
T1
teratogenic exposure at ______ stage results in more functional and minor structural defects?
growth/fetal stage
weeks 9-deliver
T2/3
teratogenic exposure at weeks 1-2 result in _______
no pregnancy
typically an all or nothing mechanism
what are 4 buckets of teratogens?
- physical agents
- chemical/substances
- maternal metabolic conditions
- infectious agents
walk me through physical agents as teratogens
Radiation
Result: congenital malformations
States of hyperthermia (hot tubs and saunas)
Result: associated with NT defects, spontaneous abortions, CV abnormalities
walk me though how maternal metabolic conditions can act as a teratogen
PKU - toxic build up to fetus of phenylalanine
hyper or hypothyroidism ➔ congenital versions (hyper w/Graves ➔ resolves once mom’s Ab are broken down postpartum)
uncontrolled DM ➔ increase risk of congenital abnormalities and hypoglycemic at birth
Lupus/SLE ➔ ab cross placenta ➔ neonatal lupus or congenital defects
walk me through infectious agents as teratogenic agents
can result in congenital infection postpartum
can also result in cx during pregnancy and the development of congenital abnormalities
ex. rubella, CMV, parvovirus, group B strep, varicella, toxoplasmosis, syphilis, chlamydia, zika
what is the TORCH infections for teratogens?
TORCH
T=toxoplasmosis, O=other (syphilis), R=rubella, C=CMV, H=herpes simplex
list 5 common chemical teratogens
- alcohol/cocaine/marijuana
- smoking
- NSAIDs
- ACEi
- Vitamin A derivatives - retinoids
- statins
- anticoagulants - warfarin - war on baby
- antidepressants
- antipsychotics
- antimicrobials
a pregnant pt on ACEi should be switched to _____
an alternative medication that is safe for pregnancy like labetalol a beta blocker
a preg pt taking regular NSAIDs should be counselled to _____
stop taking NSAIDs, use Tylenol instead
caveat, ASA is safe in preg at low doses to tx preeclampsia
what are some common anti-epileptic teratogenic medications?
Valproic acid
Carbamazepine
Phenytoin
Topiramate
what is a common bipolar/depression teratogenic medication?
lithium
how do you adjust teratogenic anti-epileptic medications for the pregnant pt?
- switch to a less teratogenic anti-seizure if possible
- reduce the dosage as much as possible
- keep mom stable but aware of the risks to baby
risk of mom > risk to baby
how do you adjust teratogenic bipolar medication for the pregnant pt?
- switch to non-teratogenic medications
- stop meds if possible
- reduce dosage if possible
- if not possible then inform of the possible congenital anomalies - cardiac anomaly
- monitor fetal HR during pregnancy
maternal risk > fetal risk
