Between 1957 and 1961, many pregnant women took thalidomide to alleviate morning sickness; this drug disrupted a(n) period of prenatal development. sensitive critical early late

Between 1957 and 1961, many pregnant women took thalidomide to alleviate morning sickness; this drug disrupted a critical period of prenatal development. This was during post-war when people were taking drugs as tranquilizers or sleeping pills. Originally, thalidomide was marketed as a mild sleeping pill and later on as a drug to alleviate morning sickness. It was then presumed that the drug was safe even for the mother and child. Some children were born with phocomelia, a rare and severe birth defect that results to the shortening or absence of the limbs. Later studies have found that thalidomide causes damage to the forming embryo during a critical period, between 20-30 days after fertilization. 

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