Embryology

د.منى زهير/ lec:7
Infectious diseases :
1-Rubella (German Measles)
2-Cytomegalovirus
3-Syphylis
4-Toxoplasmosis.

Rubella (German Measles):

The effect of Rubella on the growing fetus are the following features:
Congenital cataract
Congenital deafness.
Mental retardation
Congenital heart defects.
Occasionally defect in the enemal layer of teeth.
The effect depend on the time of exposure of the pregnant mother to Teratogenic agent …in cases of Rubella virus if the mother catch it at about 6 th weeks of pregnancy,then at birth we can see most of the features of Rubella mainly Congenital Cataract,but if it get it at 8-9 weeks of development ,there will be Congenital deafness but no effect on the eyes ( no congenital cataract).
Cytomegalovirus infection Toxoplasmosis
1-Complete loss of vision 1-Partial loss of vision
2-Intracranial calcification 2-Intracranial calcification
3-Microcephally 3-Hydrocephally
4-Delayed and severe degree of 4-Mental mental Mental retardation
5-Hepatosplenomegally 5- Microphthalmous other
6- Kerniecterus and severe mental 6- occular defects
Retardation due to jaundice.


Syphilis leads to following features in new born baby:
1-Cleft lip and palate ( very high incidence )
2-Spina bifida.

Radiation and Antitoxic drugs:

Has a direct effect on developing fetus as there is a strong association between exposure to radiation and the appearance of congenital malformations and the same can happen on taking anti-toxic drugs.An example for the effect of adiation is what has happened in Japan during 2nd world war in 1945 as a resut of atomic bombs thrown on Hiroshima and Nagazaki .All females in these 2 cities remained alife after bombing and became pregnant later on a survey was done and showed that 28% were aborted ,25% has intrauterine death of fetuses,25% of babies born alive were died during the first year of age and the remaining showed chromosomal defects and mutations.