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Oliver Wendell Holmes is credited with introducing the words "anesthesia" and "anesthetic" into the English language in 1846.
More than 2,500 barbiturates have been synthesized. At the height of their popularity, about 50 were marketed for human use.
Sperm cells are so tiny that 400 to 500 million (400,000,000–500,000,000) of them fit onto 1 tsp.
Thyroid conditions may make getting pregnant impossible.
There are approximately 3 million unintended pregnancies in the United States each year.
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