Answer:
The answer is: Critical period
Explanation:
Thalidomide is an immunomodulatory drug, which is prescribed as a tranquilizer or hypnotic for insomnia, anxiety and gastritis.
When administered by pregnant women during the first and the second trimester, this drug caused teratogenic deformities in the newborns.
The deformity caused depends majorly on how many days into the pregnancy the mother administered the drug. If the drug is taken up to day 28, it causes damage to the legs. This is because it is a critical period for the development of legs.
Critical period refers to the stage of development of the child. During this stage, the central nervous system is very sensitive to certain environmental stimuli.
