Quotation Marks are not for emphasis

Have you ever seen a sign like this and wondered what it meant. Why the quotes? We can assume that the writer is trying to highlight or emphasize "pregnant" as it's serious business not to x-ray a patient who might be pregnant. 

However, in American English, quotes around a word are our way of indicating the opposite of the original meaning, sort of like air quotes around a word. 

There's a right way to make this sign. What do you think it is? 

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