applied embryology Flashcards
What are the most common anomalies?
congenital heart defects
how many babies are affected by neural tube defects?
1 in 1,000
what is the prognosis for those with congenital heart defects?
6% die before their first birthday
what percentage of babies are born with birth defects?
2.2%
what is a teratogen?
environmental exposure which can result in birth defects in the foetus
- drug, substance or infection
what effects can teratogens have on the developing foetus?
- developmental delay: learning difficulties
- structural abnormalities: growth defects
- cancer
- death
when do structural defects take place?
first trimester during organogenesis
greatest risk: weeks 3 - 11
when are functional and growth defects most likely to occur?
after 12 weeks
examples of drug teratogens
- carbamazepine
- phenytoin
- sodium valproate
- retinoids
- thalidomide
- tetracyclines
- diethylstilboesterol
- alcohol, cigarette smoke, illegal drugs
what is binge drinking?
individual drinks 5 or more units of alcohol on one occasion
when is binge drinking particularly harmful?
around conception and in early pregnancy
what is heavy drinking often related to?
unprotected sex which may lead to unplanned pregnancies and STIs
what is the classic triad for congenital rubella syndrome?
- sensorineural deafness
- eye abnormalities: retinopathy, cataract and microphthalmia)
- congenital heart disease: pulmonary artery stenosis and patent ductus arteriosus
what can varicella in a foetus lead to?
- limb hypoplasia
- skin scarring
- eye defects
when does varicella pose the greatest risk to foetuses?
2nd trimester
