Chapter 12 - Effects on the Embryo and Fetus Flashcards
What are the three effects induced by radiation on the fetus?
1) Lethal
2) Malformations
3) Growth disturbances and growth retardation
What is the average malformation percentage in infants?
6%
What is the average malformation percentage in children?
12%
What periods of development are most important when describing the effect of radiation?
Preimplantation
Organogenesis
Fetal Period
What are normally the effects of radiation during preimplantation?
“All or nothing”.
Either the embryo dies or it lives with no adverse effects
What are the normal effects of radiation during organogenesis?
Congenital abnormalities
Growth retardation - temporary
On the basis of animal experiments, does there seem to be a threshold for abnormalities seen in organogenesis?
Yes 100mGy
What is the normal time for the fetal period?
6 weeks and on
What are the effects from radiation seen at the fetal period in animals?
Permenant growth retardation
Organ fuck ups
What were the main side effects to embryos in the A bomb study?
Microcephaly
Mental retardation.
What were the main side effects to embryos with exposure to medical radiation?
First 3 weeks - death
4-11 weeks - severe organ abnormalities
11-16 weeks - stunted growth, microcephaly and mental retardation
After 16 weeks- stunted growth, microcephaly and mental retardation
Cancer in fetus that were exposed to radiation can do what?
Go up - leukemia 2.4 times higher
One x-ray exam can result in how much higher risk of cancer over the spontaneous level?
40%
What is the increased risk per grey?
6%
What is the monthly limit recommended for the embryo by the national council on Radiological Protection and measurements?
0.5mSv
