DEVELOPMENTAL DISORDERS -
Inflammation of amnion due to infection.
Escape of a embryo prior to the stage of viability (about 20 weeks of gestation, foetal weight is less than 500 gm.) occuring by natural causes.
It is different from premature birth.
Note :- A premature infant is born after the stage of mobility but before full term.
3. TERATOGENY -
Production of malformed infant due to use of tobacco, alcohol & drugs by pregnant mother.